756 lines
53 KiB
HTML
756 lines
53 KiB
HTML
<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8" />
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<meta name="viewport" content="width=device-width, initial-scale=1.0" />
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<title>About SunScope · The True Temperature</title>
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<meta name="description" content="SunScope uses the Universal Thermal Climate Index (UTCI) and an original soak-factor formula to show how the weather will really feel on your body — including the effect of rain, snow, wind, solar radiation, air quality, pollen, and visibility." />
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<meta name="robots" content="index, follow" />
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<link rel="canonical" href="https://sunscope.net/about.html" />
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<meta property="og:title" content="About SunScope · The True Temperature" />
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<meta property="og:description" content="What is UTCI? How does the SunScope soak-factor work? Learn how SunScope calculates urban concrete heat, vehicle interior temperatures, and gives you a more honest outdoor comfort forecast." />
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<link rel="stylesheet" href="./assets/about.css">
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<script type="application/ld+json">
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{
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"@context": "https://schema.org",
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"@type": "WebApplication",
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"name": "SunScope",
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"url": "https://sunscope.net",
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"description": "A free hourly UTCI thermal comfort forecast combining air temperature, humidity, wind speed, and solar radiation. Includes vehicle interior temperature, indoor temperature, UV burn time, concrete surface temperature, soil data, air quality index, pollen, and visibility.",
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"name": "SunScope",
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"url": "https://sunscope.net",
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"description": "SunScope is a free outdoor thermal comfort forecast using the Universal Thermal Climate Index (UTCI) and the SunScope soak-factor for precipitation."
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}
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</script>
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<script type="application/ld+json">
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{
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"mainEntity": [
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{
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"@type": "Question",
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"name": "What is UTCI and why is it better than a standard feels-like temperature?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "The Universal Thermal Climate Index (UTCI) is a peer-reviewed biometeorological standard developed by Bröde et al. (2012) and used in public health systems worldwide. Unlike simple feels-like values that only apply wind-chill or heat-index formulas, UTCI combines air temperature, humidity, wind speed, and the full solar radiation load using a physiological model of the human body. It accounts for mean radiant temperature from all surrounding surfaces, making it a much more accurate predictor of actual thermal comfort and heat stress."
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}
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},
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{
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"@type": "Question",
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"name": "What is the SunScope soak-factor?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "The SunScope soak-factor is an original precipitation penalty formula that reduces the UTCI felt-temperature value based on rain intensity, snowfall, and wind speed — reflecting the extra chill of wet clothing and skin that standard UTCI does not account for. The result is shown as UTCI+P."
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}
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},
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{
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"@type": "Question",
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"name": "How hot does a car get in the sun?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "A sealed car in direct sunlight can reach cabin temperatures 20–30 °C above outside air temperature within 30–45 minutes. On a 25 °C day with strong sun, cabin air can hit 50–55 °C. SunScope models this hour by hour using the actual solar radiation forecast, accounting for body panel conduction and window solar gain. Motorhomes and caravans are treated separately as insulated occupied living spaces, with reflective panels, retained warmth, and slower heat response. Values above 35 °C are dangerous for children and pets; above 45 °C can be fatal within minutes."
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}
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},
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{
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"@type": "Question",
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"name": "Does opening car windows reduce the temperature inside?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Yes, significantly. Open windows allow convective airflow to flush hot cabin air out continuously, reducing heat build-up by roughly 60–80% compared to a sealed vehicle. SunScope's Vehicle column includes a Windows open toggle that switches the physics model to a ventilated state, showing you the estimated cabin temperature with windows cracked compared to fully sealed."
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}
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},
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{
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"@type": "Question",
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"name": "Is it safe to leave a dog in a parked car?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "No — on any warm or sunny day a sealed vehicle heats up rapidly to temperatures that can cause heatstroke and death in animals within minutes. Dogs cannot cool themselves as efficiently as humans and are at risk at cabin temperatures above 32 °C. SunScope's Vehicle interior column gives an hour-by-hour estimate of cabin temperature so you can see at a glance whether conditions are safe."
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}
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},
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{
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"@type": "Question",
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"name": "How do I keep my house cool in a heatwave without air conditioning?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Keep curtains and blinds closed during the day to block direct solar gain, then open windows once outdoor air drops below the indoor temperature — usually in the evening or early morning. SunScope's Home profile lets you select your building type (brick, modern, Victorian terrace, stone cottage, timber frame, flat, or conservatory) so the model reflects how your building actually heats up. Ticking Managed shows the effect of following this advice hour by hour — so you can see exactly when to open up and how much difference it makes."
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}
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},
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{
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"@type": "Question",
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"name": "Why is my house hotter in the evening than during the day?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Building materials absorb heat slowly throughout the day and release it gradually over several hours — a property called thermal mass. How pronounced the effect is depends on construction: a stone cottage or Victorian terrace stays warm well into the night, while a timber frame new build or conservatory responds almost immediately to outdoor changes. SunScope's building type selector lets you match the model to your actual home so the indoor temperature lag it shows reflects your building rather than an average."
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}
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},
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{
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"@type": "Question",
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"name": "How hot does pavement or concrete get in summer?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Exposed concrete and tarmac can be 15–25 °C hotter than the surrounding air on a sunny day. Unlike grass they have no evaporative cooling and absorb a large fraction of solar radiation. This is a hazard for dogs on pavements, barefoot children, and cyclists. SunScope's Concrete surface column estimates this temperature using an energy-balance model driven by the real solar radiation forecast."
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}
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},
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{
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"@type": "Question",
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"name": "What is the difference between UV-A and UV-B?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "UV-A has a longer wavelength and penetrates deeper into the skin. It is present throughout all daylight hours, passes through glass, and is the primary cause of long-term skin ageing. UV-B has a shorter wavelength, causes sunburn directly, and drives vitamin D production. UV-B intensity falls sharply at low solar elevations. SunScope shows both indices separately so you can make informed decisions about both immediate burn risk and long-term UV exposure."
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}
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},
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{
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"@type": "Question",
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"name": "How long can I spend in the sun before I get sunburned?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "It depends on your skin type and the current UV index. SunScope's Burn time column estimates the minutes to one Minimal Erythemal Dose (MED) — the threshold for the onset of sunburn — based on the UV forecast and your Fitzpatrick skin type. Fair skin (type I–II) may burn in under 10 minutes at UV index 8+; darker skin can tolerate significantly longer exposure. Figures assume no sunscreen and direct unshaded exposure."
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}
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},
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{
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"@type": "Question",
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"name": "What soil temperature do seeds need to germinate?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Most vegetable seeds need soil temperatures above 7–10 °C to germinate reliably, with warm-season crops like courgettes and beans requiring 12–15 °C or more. SunScope shows both surface soil temperature and 6 cm depth temperature — the root zone where germination actually happens — so you can time sowing decisions accurately."
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}
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},
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{
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"@type": "Question",
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"name": "How can I tell if the ground is too wet for a motorhome or caravan?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "SunScope's soil moisture column shows volumetric water content in m³/m³. A reading above 0.4 indicates saturated ground where a heavy vehicle is likely to sink or churn the surface. Below 0.2 is dry and firm. The Vehicle profile includes soil moisture by default for motorhome and caravan users assessing pitch suitability."
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}
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},
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{
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"@type": "Question",
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"name": "What is the difference between UTCI and heat index?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Heat index is a simple table-based formula that adjusts air temperature for humidity only — it was designed for shade conditions and ignores wind and solar radiation. UTCI is a full physiological model accounting for all four factors simultaneously: air temperature, humidity, wind speed, and mean radiant temperature from solar radiation and surrounding surfaces. In sunny or windy conditions the two values can differ by 10–20 °C. UTCI is the standard used in European heat-health warning systems."
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}
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},
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{
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"@type": "Question",
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"name": "How accurate is SunScope?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "SunScope uses Open-Meteo forecast data sourced from ECMWF and national meteorological services. The UTCI calculation follows the peer-reviewed Bröde 2012 polynomial exactly. Derived columns (vehicle temperature, indoor temperature, concrete surface, UV) are physics-based estimates rather than measured values, and will vary based on local factors like building construction, shading, and surface colour."
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}
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},
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{
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"@type": "Question",
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"name": "Does SunScope work outside the UK?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Yes — SunScope works for any location worldwide. Search for any city, town, or village using the search bar. The indoor temperature model offers seven building types — brick, modern insulated, Victorian terrace, stone cottage, timber frame, top-floor flat, and conservatory — so you can match the model to your actual building wherever you are. All other columns are fully location-agnostic."
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}
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},
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{
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"@type": "Question",
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"name": "How far ahead does the forecast go?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "The free tier shows 3 days of hourly data. The forecast auto-refreshes every 5 minutes while the page is open, so the current hour always reflects the latest available data from Open-Meteo."
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}
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},
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{
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"@type": "Question",
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"name": "Does SunScope show air quality and pollen forecasts?",
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"acceptedAnswer": {
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"@type": "Answer",
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"text": "Yes. SunScope includes three air environment columns: Visibility (horizontal visibility in km, useful for fog, haze, and driving conditions), AQI (European Air Quality Index combining PM2.5, PM10, ozone, NO2, and SO2, sourced from Copernicus CAMS), and Pollen (concentration in grains per cubic metre with a selectable pollen type — grass, birch, alder, mugwort, olive, ragweed, or total). These columns appear after Cloud in the table and can be toggled on or off in the column bar."
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}
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}
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]
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}
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</script>
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</head>
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<body>
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<header id="site-nav">
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<div class="nav-overlay" onclick="toggleNav(false)"></div>
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<a href="./index.html" class="logo"><span class="logo-sun">SUN</span><span class="logo-scope">Scope</span></a>
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<div class="nav-links" id="nav-drawer">
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<a href="./index.html">Forecast</a>
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<a href="./about.html" class="active">About</a>
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<a href="./faq.html">FAQ</a>
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<a href="https://billing.stripe.com/p/login/9B63cw7vl8k15Ei9DQd7q00" target="_blank" rel="noopener noreferrer">Account</a>
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</div>
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<button class="utci-burger" aria-label="Open menu" aria-expanded="false" id="burger-btn" onclick="toggleNav()">
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<span></span><span></span><span></span>
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</button>
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</header>
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<script>
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function toggleNav(force) {
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const nav = document.getElementById('site-nav');
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const drawer = document.getElementById('nav-drawer');
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const btn = document.getElementById('burger-btn');
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}
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</script>
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<main>
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<h1>About SunScope</h1>
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<p class="tagline">The True Temperature — what the weather actually feels like on your body.</p>
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<h2>What is SunScope?</h2>
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<p>
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SunScope is a free outdoor thermal comfort forecast that goes well beyond standard air
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temperature. Most weather apps tell you it's 12 °C and leave you to guess whether that means
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a t-shirt or a heavy coat. SunScope combines air temperature, humidity, wind speed, and solar
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radiation into a single <strong>felt temperature</strong> — so you know what to actually expect
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when you step outside.
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</p>
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<p>
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The core calculation is the <strong>Universal Thermal Climate Index (UTCI)</strong>, a
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peer-reviewed biometeorological standard developed by
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<a href="https://utci.org/" target="_blank" rel="noopener noreferrer">Bröde et al. (2012)</a>
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and used globally in heat-health warning systems and urban planning. On top of that, SunScope
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layers its own <strong>soak-factor</strong> precipitation penalty — because UTCI alone doesn't
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account for the extra chill of rain soaking through your clothes on a windy day. The combined
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result is the <strong>UTCI+P</strong> score: a more honest, real-world comfort number.
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</p>
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<p>
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Forecast data is sourced in real time from <strong>Open-Meteo</strong>, a free and open-source
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weather API drawing on ECMWF and national meteorological services. The forecast refreshes
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automatically every five minutes and is available for any location worldwide.
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</p>
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<h2>What else does SunScope calculate?</h2>
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<p>
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SunScope goes far beyond a single felt-temperature number. Depending on the profile you choose,
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it can calculate and display a wide range of derived quantities, each built on the same
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per-hour weather data:
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</p>
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<p>
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<strong>Vehicle interior temperature.</strong> A physics-based model estimates how hot a sealed,
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parked vehicle gets over time — combining heat conducted through the roof and body panels with
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direct solar gain through the side windows. You can select your vehicle type (car, MPV, SUV,
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motorhome, or caravan), each of which has its own albedo, glazing area, and insulation
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characteristics. A <em>Windows open</em> toggle switches to a ventilated model where convective
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loss is roughly five times higher, dramatically reducing cabin heat build-up — mirroring the
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real-world effect of cracking the windows.
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</p>
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<p>
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<strong>Indoor temperature.</strong> The <em>Indoors</em> column estimates the temperature
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inside a building with windows closed and no air conditioning, simulating retained warmth,
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window solar gain, internal gains, and thermal mass hour by hour. You choose your building type from a dropdown
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— brick, modern insulated, Victorian terrace, stone cottage, timber frame, top-floor flat, or
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conservatory — and the physics model adjusts accordingly. Each type has its own insulation
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level, thermal mass, retained warmth, and glazing characteristics, so a stone cottage and a conservatory behave
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very differently on a hot day. The model now lags toward a realistic hourly target rather
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than repeatedly adding solar heat, so indoor temperatures typically peak 2–4 hours after the outdoor
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peak, which is why a house can still feel stifling at 10 pm on a summer day. Tick
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<em>Managed</em> alongside the dropdown to switch to the heatwave-advice model: curtains
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closed by day to cut solar gain, windows opened whenever outdoor air is cooler than inside.
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</p>
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<p>
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<strong>Urban concrete surface temperature.</strong> Concrete and tarmac absorb far more solar
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energy than grass, and unlike grass they have no evaporative cooling. On a sunny summer
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afternoon, exposed paving can run 15–25 °C hotter than the surrounding air. SunScope models
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this using a surface energy balance approach that accounts for solar absorption, surface
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emissivity, and convective cooling by wind.
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</p>
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<p>
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<strong>UV and sunburn.</strong> SunScope splits the solar UV spectrum into UV-A and UV-B
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components. The burn-time column estimates how long before you reach one Minimal Erythemal
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Dose (the clinical threshold for sunburn) based on the UV index and your Fitzpatrick skin type
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— selected from a dropdown in the column bar.
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</p>
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<p>
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<strong>Soil temperature and moisture.</strong> Surface and 6 cm soil temperatures are shown for
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agricultural and outdoor-work planning. Soil moisture indicates whether the ground is workable
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or saturated — particularly useful for motorhome and caravan pitching.
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</p>
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<p>
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<strong>Air quality, visibility, and pollen.</strong> Three atmospheric columns sit together
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after cloud cover in the table. <em>Visibility</em> shows horizontal visibility in kilometres,
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sourced from the CAMS model — values below 1 km indicate fog, below 10 km suggest mist or
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pollution haze. <em>AQI</em> shows the European Air Quality Index (0–100+), combining PM2.5,
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PM10, ozone, nitrogen dioxide, and sulphur dioxide, with colour-coded bands from Good to
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Hazardous. <em>Pollen</em> shows concentration in grains per cubic metre for a selectable
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pollen type — choose from total pollen, grass, birch, alder, mugwort, olive, or ragweed — with
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Low / Moderate / High / Very High labels. All three are sourced from the Copernicus CAMS
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air quality forecast.
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</p>
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<p>
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<strong>The sky scope.</strong> The large circular visualisation at the top of the page shows
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the sky conditions for the currently selected hour. The sky colour smoothly interpolates through
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a full set of elevation-keyed gradients — from deep pre-dawn navy through golden sunrise, bright
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midday blue, warm sunset amber, and back to night — with a sun disc whose glow radius and
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intensity scale with the actual shortwave radiation at that moment. It refreshes automatically
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alongside the forecast.
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</p>
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<p>
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<strong>Day strip weather and temperatures.</strong> Each day tab in the date selector shows the
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day's forecast at a glance: a weather icon representing the dominant daytime conditions (sun,
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cloud variants, or precipitation), plus the day's high and low UTCI+P felt temperatures in
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warm and cool colours. The icon uses the actual daytime solar elevation and cloud category data
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so it reflects the real character of the day rather than a generic symbol.
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</p>
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<p>
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<strong>Weather event banners and popups.</strong> When notable weather conditions are forecast
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— such as a frost, strong winds, fog, or a heat event — a banner appears above the forecast
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table with a brief alert. Tapping or clicking the event icon opens a detailed description
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popup explaining what the condition means and what to watch out for.
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</p>
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<p>
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<strong>What's Coming — cosmic events almanac.</strong> A 🔭 panel below the forecast table
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shows upcoming astronomical events for your location over the next 90 days: meteor showers,
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lunar and solar eclipses, planetary conjunctions, and oppositions. Each entry shows the event
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name, peak date, a countdown, a short description, and a visibility note where the event is
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better from a particular hemisphere or location. When a cosmic event is currently active,
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it also appears as a banner above the forecast table alongside the weather alerts.
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</p>
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<h2>What is the SunScope soak-factor?</h2>
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<p>
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Standard UTCI does not account for precipitation — it tells you how cold the wind and sun make
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you feel, but not the extra chill of rain soaking your clothing or snow settling on your skin.
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The <strong>SunScope soak-factor</strong> fills that gap with an original penalty formula.
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</p>
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<p>
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Light drizzle (under 1 mm/hr) reduces the felt temperature by roughly 1–2 °C. Heavy rain
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combined with strong wind can push it down by 7–8 °C. Snowfall carries an additional penalty
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on top of any rain adjustment. The result is shown in the <strong>UTCI+P</strong> column —
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a more honest, real-world comfort score for anyone heading outdoors.
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</p>
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<h2>Forecast profiles</h2>
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<p>
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SunScope organises its columns into <strong>profiles</strong> — curated sets of data tailored
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to different activities and use cases. Rather than showing every column at once, each profile
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surfaces the information that actually matters for that situation. You can switch between
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<strong>Basic</strong>, <strong>Home</strong>, and <strong>Vehicle</strong> using the buttons
|
||
above the forecast table. Two dropdowns — <strong>Places</strong> and <strong>Activities</strong>
|
||
— give access to a further set of tailored views. The Temps comparison and Custom column
|
||
builder are part of SunScope Extra.
|
||
</p>
|
||
|
||
<div class="profile-block">
|
||
<p class="profile-name">🌡️ Basic</p>
|
||
<p>
|
||
The default view — clean and uncluttered, showing the essentials for any outdoor situation.
|
||
<strong>Air temperature</strong>, <strong>wind speed</strong>, <strong>cloud cover</strong>,
|
||
<strong>visibility</strong>, <strong>precipitation</strong>, and <strong>UTCI+P</strong> — the adjusted felt temperature
|
||
that combines sun, wind, humidity, and rain into a single honest number. The right starting
|
||
point for most people most of the time.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="profile-block">
|
||
<p class="profile-name">🏠 Home</p>
|
||
<p>
|
||
For managing indoor comfort without air conditioning. The indoor temperature column is
|
||
central: select your building type from the dropdown (UK brick, modern insulated, Victorian
|
||
terrace, stone cottage, timber frame, top-floor flat, or conservatory) and the physics model
|
||
adjusts for that building's insulation, retained warmth, thermal mass, and glazing
|
||
characteristics. Tick <strong>Managed</strong> to switch to the heatwave-advice model —
|
||
curtains closed by day to block solar gain, windows opened whenever outdoor air is cooler
|
||
than inside. Indoor temperatures typically peak 2–4 hours after the outdoor peak due to
|
||
thermal mass, and the model reflects this lag for each building type. Supporting columns
|
||
include <strong>air temperature</strong>, <strong>relative humidity</strong> and
|
||
<strong>dew point</strong> (important for condensation and mould risk in cooler months),
|
||
<strong>wind speed</strong> for ventilation decisions, <strong>cloud cover</strong>,
|
||
<strong>air quality index</strong> and <strong>pollen</strong> (useful for allergy
|
||
sufferers deciding whether to open windows), and <strong>precipitation</strong> — so
|
||
you know whether to open the windows or bring the washing in.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="profile-block">
|
||
<p class="profile-name">🚗 Vehicle</p>
|
||
<p>
|
||
Covers the parked and travelling vehicle experience — especially useful for anyone with
|
||
children or pets, motorhome travellers, and caravan owners. The headline column is
|
||
<strong>vehicle interior temperature</strong>: a physics-based estimate of how hot the
|
||
cabin gets when parked and sealed, adjusted for your chosen vehicle type (car, MPV, SUV,
|
||
motorhome, or caravan). Motorhomes and caravans are treated as insulated occupied living
|
||
spaces, with reflective sandwich panels roughly 25–35 mm thick, less sun-exposed glass
|
||
than a car, and retained warmth from previous hours, occupants, appliances, and background
|
||
heating. <strong>Wind speed</strong> is included because it matters significantly for
|
||
high-sided vehicles and caravans. <strong>Cloud cover</strong> and <strong>air
|
||
temperature</strong> give context, <strong>precipitation</strong> covers driving
|
||
conditions, and <strong>UTCI+P</strong> tells you what it will feel like when you step
|
||
outside. <strong>Soil moisture</strong> is included specifically for motorhome and caravan
|
||
users — values above 0.4 m³/m³ indicate saturated ground where pitching or manoeuvring
|
||
is likely to cause problems.
|
||
</p>
|
||
</div>
|
||
|
||
|
||
<div class="profile-block">
|
||
<p class="profile-name">🌤️ Places</p>
|
||
<p>
|
||
The Places dropdown gives access to seven location-specific views, each with its own
|
||
tailored column set. Urban, Beach, Events, Park/Picnic, and Airport/Travel are free;
|
||
Festival and Construction are part of SunScope Extra.
|
||
</p>
|
||
<p>
|
||
<strong>Urban</strong> — designed for anyone moving around a city on foot: commuting,
|
||
shopping, sightseeing. The urban environment creates its own microclimate: buildings
|
||
channel wind into gusts down narrow streets, concrete absorbs heat all day and radiates
|
||
it back long after sunset, and the lack of vegetation means there's no evaporative
|
||
cooling. Columns: <strong>air temperature</strong>, <strong>wind speed and direction</strong>,
|
||
<strong>cloud cover</strong>, <strong>visibility</strong>, <strong>air quality index</strong>,
|
||
<strong>UV-A index</strong>, <strong>burn time</strong>, <strong>UTCI+P</strong>,
|
||
<strong>precipitation</strong>, and <strong>concrete surface temperature</strong>.
|
||
</p>
|
||
<p>
|
||
<strong>Beach</strong> — UV exposure at the coast is significantly higher than inland:
|
||
water reflects up to 25% of incoming UV back at you, and wet sand nearly as much. Both
|
||
<strong>UV-A</strong> and <strong>UV-B</strong> are shown alongside <strong>burn
|
||
time</strong> for your skin type. <strong>Dew point</strong> captures the humidity that
|
||
makes hot beach days feel muggy, <strong>wind speed and direction</strong> matters for
|
||
comfort and sea state, and <strong>sun elevation</strong> tells you when the UV load
|
||
peaks. <strong>Visibility</strong> is included for sea-state and horizon conditions.
|
||
<strong>UTCI+P</strong> and <strong>precipitation</strong> round out the picture.
|
||
</p>
|
||
<p>
|
||
<strong>Events</strong> — for general outdoor gatherings: markets, sports fixtures, open-air
|
||
concerts, and public events. Focuses on the crowd comfort picture: <strong>air
|
||
temperature</strong>, <strong>wind speed and direction</strong> (useful for exposed
|
||
grandstands and open sites), <strong>cloud cover</strong>, <strong>UV-A</strong> and
|
||
<strong>burn time</strong> for daytime events, <strong>UTCI+P</strong> for overall felt
|
||
comfort, <strong>precipitation</strong>, <strong>pollen</strong> (important for
|
||
allergy-sensitive attendees), and <strong>concrete surface temperature</strong>
|
||
— relevant for anyone standing or sitting on sun-exposed hard standing for extended periods.
|
||
</p>
|
||
<p>
|
||
<strong>Park / Picnic</strong> — a lighter view for casual outdoor time in green spaces.
|
||
Shows the essentials without the urban or specialist columns: <strong>air temperature</strong>,
|
||
<strong>wind speed</strong>, <strong>cloud cover</strong>, <strong>burn time</strong>,
|
||
<strong>UTCI+P</strong>, <strong>precipitation</strong>, and <strong>pollen</strong>
|
||
— useful for anyone with hay fever deciding whether to head out.
|
||
</p>
|
||
<p>
|
||
<strong>Airport / Travel</strong> — focused on the conditions that affect journeys rather
|
||
than outdoor comfort. Shows <strong>air temperature</strong>, <strong>wind speed and
|
||
direction</strong> (relevant for delays and turbulence at exposed airports),
|
||
<strong>cloud cover</strong>, <strong>visibility</strong> (critical for flight operations
|
||
and driving to the terminal), and <strong>precipitation</strong>.
|
||
</p>
|
||
<p>
|
||
<strong>Festival · Extra</strong> — multi-day outdoor events live or die by two things: the
|
||
weather comfort and the state of the ground. Focuses on <strong>UTCI+P</strong> for how
|
||
cold and wet conditions will actually feel, <strong>wind speed and direction</strong> for
|
||
tent and stage exposure, <strong>dew point</strong> for overnight condensation,
|
||
<strong>UV-A</strong> and <strong>burn time</strong> for daytime sun protection,
|
||
<strong>precipitation</strong> for planning, <strong>air quality index</strong> and
|
||
<strong>pollen</strong> — particularly relevant for multi-day outdoor exposure — and
|
||
<strong>soil moisture</strong> — the mud indicator. Values above 0.4 m³/m³ mean the ground
|
||
is saturated and vehicle access, camping areas, and walkways will be affected.
|
||
</p>
|
||
<p>
|
||
<strong>Construction · Extra</strong> — for site managers and outdoor workers. Safety and
|
||
productivity on a construction site depend on conditions at ground level and in the air.
|
||
Shows <strong>air temperature</strong>, <strong>wind speed and direction</strong> (critical
|
||
for working at height and crane operations), <strong>cloud cover</strong>,
|
||
<strong>visibility</strong>, <strong>air quality index</strong> (dust and diesel
|
||
particulates compound background pollution), <strong>UTCI</strong> for heat stress on
|
||
workers, <strong>UTCI+P</strong> for wet-weather comfort, and <strong>precipitation</strong>.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="profile-block">
|
||
<p class="profile-name">🎯 Activities</p>
|
||
<p>
|
||
The Activities dropdown organises views by what you are actually doing outdoors. Farming,
|
||
Cycling, Running, and Dog Walking are free; Sailing, Winter Sports, Naturist, Hiking,
|
||
Photography, and Fishing are part of SunScope Extra.
|
||
</p>
|
||
<p>
|
||
<strong>Farming</strong> — built for anyone working the land: farmers, growers, and market
|
||
gardeners. Decision-making in agriculture is driven by conditions at ground level, not just
|
||
the air. Shows <strong>air temperature</strong>, <strong>relative humidity</strong> and
|
||
<strong>dew point</strong> (critical for frost risk and disease pressure on crops),
|
||
<strong>wind speed and direction</strong> (essential for safe spraying windows),
|
||
<strong>cloud cover</strong> and <strong>sun elevation</strong> for light levels,
|
||
<strong>UTCI+P</strong> for heat stress on the person working outdoors,
|
||
<strong>precipitation</strong>, <strong>air quality index</strong> and <strong>pollen</strong>
|
||
(relevant for outdoor workers and spray-window planning), and the three soil columns:
|
||
<strong>surface soil temperature</strong>, <strong>soil temperature at 6 cm</strong>
|
||
(the root zone for most seedlings), and <strong>soil moisture</strong> — so you know
|
||
whether the ground is workable or waterlogged before you head out.
|
||
</p>
|
||
<p>
|
||
<strong>Cycling</strong> — tailored for road and trail cyclists. Wind is the dominant
|
||
factor: headwinds add significant effort, crosswinds affect handling, and gusts are a
|
||
safety concern on open roads. Shows <strong>air temperature</strong>, <strong>wind speed
|
||
and direction</strong>, <strong>cloud cover</strong>, <strong>burn time</strong>,
|
||
<strong>UTCI+P</strong>, <strong>precipitation</strong>, and <strong>visibility</strong>
|
||
— useful for road cycling in low-light or foggy conditions.
|
||
</p>
|
||
<p>
|
||
<strong>Running</strong> — for outdoor runners monitoring heat stress and air quality.
|
||
Shows <strong>air temperature</strong>, <strong>relative humidity</strong> (sweat
|
||
evaporation is less effective in humid air, raising heat stress faster),
|
||
<strong>wind speed</strong>, <strong>cloud cover</strong>, <strong>UTCI</strong> for raw
|
||
heat stress, <strong>burn time</strong>, <strong>UTCI+P</strong>, <strong>precipitation</strong>,
|
||
and <strong>pollen</strong> — relevant for asthma and hay fever sufferers pacing their
|
||
outdoor training.
|
||
</p>
|
||
<p>
|
||
<strong>Dog Walking</strong> — focused on the comfort and safety of both owner and dog.
|
||
Shows <strong>air temperature</strong>, <strong>wind speed</strong>, <strong>cloud
|
||
cover</strong>, <strong>UTCI+P</strong>, <strong>precipitation</strong>, and
|
||
<strong>pollen</strong>. The Vehicle profile's concrete surface temperature is the better
|
||
companion for pavement heat safety on hot days.
|
||
</p>
|
||
<p>
|
||
<strong>Sailing · Extra</strong> — conditions out at sea can be dramatically different from
|
||
what the shore feels like. Leads with <strong>air temperature</strong> (hypothermia is a
|
||
real risk — water conducts heat away from the body twenty-five times faster than air),
|
||
<strong>dew point</strong> (condensation on sails and equipment is a practical concern at
|
||
dawn and dusk), <strong>wind speed</strong> with gusts, <strong>wind direction</strong>,
|
||
<strong>cloud cover</strong>, and <strong>sun elevation</strong> for visibility and glare.
|
||
UV exposure is significantly higher on open water due to reflection off the surface, so
|
||
<strong>UV-A index</strong> and <strong>burn time</strong> are included.
|
||
<strong>UTCI+P</strong> captures the combined effect of wet, windy conditions,
|
||
<strong>visibility</strong> (essential for safe passage — fog and haze at sea are serious
|
||
hazards), and <strong>precipitation</strong> rounds out the picture for passage planning.
|
||
</p>
|
||
<p>
|
||
<strong>Winter Sports · Extra</strong> — for skiers, snowboarders, and mountain walkers. UV
|
||
intensity increases by roughly 10% for every 1,000 m of altitude, and snow reflects up
|
||
to 80% of UV back upward — making mountain environments one of the highest-risk UV
|
||
exposures outside a solarium. Both <strong>UV-A</strong> and <strong>UV-B</strong> are
|
||
shown with <strong>burn time</strong>. <strong>Wind speed and direction</strong> is
|
||
critical for wind chill at speed and for avalanche and exposure risk on open slopes.
|
||
<strong>Sun elevation</strong> indicates glare and visibility conditions on snow.
|
||
<strong>UTCI+P</strong>, <strong>air temperature</strong>, <strong>cloud cover</strong>,
|
||
<strong>visibility</strong> (critical for whiteout and low-cloud conditions on the
|
||
mountain), and <strong>precipitation</strong> (snow vs rain) complete the picture.
|
||
</p>
|
||
<p>
|
||
<strong>Naturist · Extra</strong> — with no clothing buffer between skin and environment,
|
||
every weather variable matters more. Wind chill at even modest speeds becomes significant,
|
||
so both the raw <strong>UTCI</strong> and <strong>UTCI+P</strong> are shown. Both
|
||
<strong>UV-A</strong> and <strong>UV-B</strong> are included — full-body UV exposure is a
|
||
serious consideration — alongside <strong>burn time</strong>, <strong>sun elevation</strong>,
|
||
<strong>dew point</strong> for humidity comfort, <strong>wind</strong>, <strong>cloud
|
||
cover</strong>, <strong>air quality index</strong>, <strong>pollen</strong>,
|
||
and <strong>precipitation</strong>.
|
||
</p>
|
||
<p>
|
||
<strong>Hiking · Extra</strong> — for hillwalkers and long-distance trail users. Conditions
|
||
in upland and remote terrain can shift rapidly and the consequences of being caught out are
|
||
more serious than in urban areas. Shows <strong>air temperature</strong>, <strong>wind speed
|
||
and direction</strong>, <strong>cloud cover</strong>, <strong>sun elevation</strong>, both
|
||
<strong>UV-A</strong> and <strong>UV-B</strong> with <strong>burn time</strong> (altitude
|
||
increases UV exposure), <strong>UTCI</strong> and <strong>UTCI+P</strong>,
|
||
<strong>precipitation</strong>, and <strong>visibility</strong> (critical for navigation
|
||
in poor conditions).
|
||
</p>
|
||
<p>
|
||
<strong>Photography · Extra</strong> — for outdoor and landscape photographers who need
|
||
to understand light quality, cloud diffusion, and solar position. Shows <strong>air
|
||
temperature</strong>, <strong>cloud cover</strong>, <strong>sun elevation</strong>,
|
||
<strong>direct radiation</strong> and <strong>diffuse radiation</strong> (the ratio of
|
||
these two values determines whether light is harsh or soft), <strong>visibility</strong>
|
||
(haze and atmospheric clarity), and <strong>precipitation</strong>.
|
||
</p>
|
||
<p>
|
||
<strong>Fishing · Extra</strong> — river and sea anglers need to read conditions that most
|
||
weather apps don't surface. Shows <strong>air temperature</strong>, <strong>dew point</strong>
|
||
(morning condensation and hatch activity on rivers), <strong>wind speed and direction</strong>,
|
||
<strong>cloud cover</strong>, <strong>UTCI+P</strong> for what it will actually feel like
|
||
on an exposed bank or boat, <strong>precipitation</strong>, and <strong>visibility</strong>
|
||
for sea and estuary conditions.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="profile-block">
|
||
<p class="profile-name">🌡️ Temps · Extra</p>
|
||
<p>
|
||
A comparison view that brings all temperature-derived columns into one place:
|
||
<strong>air temperature</strong>, <strong>UTCI+P</strong>, <strong>surface soil
|
||
temperature</strong>, <strong>concrete surface temperature</strong>, <strong>vehicle
|
||
interior temperature</strong>, <strong>indoor temperature</strong>, and <strong>managed
|
||
indoor temperature</strong>. Useful for understanding how the same weather conditions
|
||
manifest across different environments simultaneously.
|
||
</p>
|
||
</div>
|
||
|
||
<div class="profile-block">
|
||
<p class="profile-name">⚙️ Custom · Extra</p>
|
||
<p>
|
||
Full control over which columns appear in the table. Toggle any combination of air
|
||
temperature, dew point, relative humidity, wind, direction, cloud, visibility, air quality
|
||
index, pollen, sun elevation, direct and diffuse radiation, mean radiant temperature,
|
||
UTCI delta, UTCI, UV-A, UV-B, burn time, vehicle interior, indoor, managed indoor,
|
||
soil temperatures, soil moisture, concrete surface, precipitation, and UTCI+P. Build
|
||
exactly the view that suits your situation.
|
||
</p>
|
||
</div>
|
||
|
||
<h2>Column reference</h2>
|
||
<p>Every column in the SunScope forecast table is described below.</p>
|
||
|
||
<table class="stress-table col-ref-table">
|
||
<thead>
|
||
<tr><th>Column</th><th>What it shows</th></tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr><td><strong>Air °C</strong></td><td>Standard air temperature at 2 m above ground — the thermometer reading. Does not account for sun, wind, or humidity.</td></tr>
|
||
<tr><td><strong>RH %</strong></td><td>Relative humidity: how much moisture the air holds as a percentage of its maximum capacity at that temperature. High RH makes warm days feel stickier and cold days feel rawer.</td></tr>
|
||
<tr><td><strong>Dew Point</strong></td><td>The temperature at which air becomes saturated and moisture begins to condense. Above 16 °C it starts to feel muggy; above 21 °C it feels oppressive. A better measure of absolute humidity than RH.</td></tr>
|
||
<tr><td><strong>Wind</strong></td><td>Mean wind speed at 10 m, with peak gust in brackets where significantly higher. Wind is the primary driver of wind chill — a key ingredient in the UTCI calculation.</td></tr>
|
||
<tr><td><strong>Dir</strong></td><td>The compass direction the wind is blowing from, shown as an arrow and abbreviated label. Useful for route planning and spray timing.</td></tr>
|
||
<tr><td><strong>Cloud</strong></td><td>Total cloud cover as a percentage of sky. High cloud blocks solar radiation, reducing daytime heating and UV exposure.</td></tr>
|
||
<tr><td><strong>Visibility km</strong></td><td>Horizontal visibility in kilometres, sourced from the Copernicus CAMS air quality model. Below 1 km indicates fog or very thick haze; below 10 km suggests mist, smoke, or significant pollution. Relevant for driving, flying, cycling, and photography.</td></tr>
|
||
<tr><td><strong>AQI</strong></td><td>European Air Quality Index (0–100+), combining PM2.5, PM10, ozone, nitrogen dioxide, and sulphur dioxide. 0–20 = Good; 20–40 = Fair; 40–60 = Moderate; 60–80 = Poor; 80–100 = Very Poor; 100+ = Hazardous. Sourced from Copernicus CAMS.</td></tr>
|
||
<tr><td><strong>Pollen</strong></td><td>Pollen concentration in grains per cubic metre for the selected pollen type — choose from total, grass, birch, alder, mugwort, olive, or ragweed via the dropdown. Sourced from the Copernicus CAMS pollen forecast. Low = <10; Moderate = 10–50; High = 50–200; Very High = 200+.</td></tr>
|
||
<tr><td><strong>Sun °</strong></td><td>The angle of the sun above the horizon in degrees. Below 0° the sun has set. The higher the elevation, the more intense the radiation reaching the ground.</td></tr>
|
||
<tr><td><strong>Direct W/m²</strong></td><td>Shortwave solar radiation arriving as a direct beam from the sun. The primary driver of skin heating on sunny days.</td></tr>
|
||
<tr><td><strong>Diffuse W/m²</strong></td><td>Solar radiation scattered from all directions across the sky. Present even under cloud cover; contributes to the overall solar heat load.</td></tr>
|
||
<tr><td><strong>Tmrt °C</strong></td><td>Mean Radiant Temperature — the temperature your skin effectively "sees" from all surrounding surfaces and the sun combined. Can exceed air temperature by 20–30 °C on a sunny day; this is why shade feels so much cooler.</td></tr>
|
||
<tr><td><strong>UTCI−Air Δ</strong></td><td>The gap between the UTCI felt temperature and the plain air temperature. A large positive value means solar radiation is adding significant heat stress beyond what the thermometer shows.</td></tr>
|
||
<tr><td><strong>UTCI °C</strong></td><td>Universal Thermal Climate Index — the raw felt temperature combining air temp, humidity, wind, and solar radiation. Does not include precipitation effects.</td></tr>
|
||
<tr><td><strong>UV-A</strong></td><td>Estimated UV-A radiation index. UV-A penetrates deeper into the skin and contributes to long-term ageing and some skin cancers, even through glass. Present throughout daylight hours.</td></tr>
|
||
<tr><td><strong>UV-B</strong></td><td>Estimated UV-B radiation index. Causes sunburn and drives vitamin D production. Intensity falls sharply at low solar elevations due to the longer atmospheric path length.</td></tr>
|
||
<tr><td><strong>Burn time</strong></td><td>Estimated time to reach one Minimal Erythemal Dose (MED) — the threshold for sunburn — based on the UV index and your selected Fitzpatrick skin type. A guide, not a medical measurement.</td></tr>
|
||
<tr><td><strong>UTCI+P °C</strong></td><td>SunScope's adjusted felt temperature: UTCI plus the soak-factor penalty for rain and snow. Wet clothing and skin can reduce the effective felt temperature by up to 8 °C in heavy, windy rain.</td></tr>
|
||
<tr><td><strong>Precip mm</strong></td><td>Expected rainfall or snowfall in mm per hour. Even light drizzle meaningfully reduces felt temperature when combined with wind.</td></tr>
|
||
<tr><td><strong>Soil °C surface</strong></td><td>Temperature of the soil at the surface (0 cm depth). Most seeds germinate above 7–10 °C. Useful for sowing decisions and frost assessment.</td></tr>
|
||
<tr><td><strong>Soil °C 6 cm</strong></td><td>Soil temperature at 6 cm depth — the root zone for many crops and seedlings. Lags behind the surface by several hours.</td></tr>
|
||
<tr><td><strong>Soil moisture</strong></td><td>Volumetric water content of the top 1 cm of soil in m³/m³. Above 0.4 indicates saturated ground; below 0.2 is dry. Useful for assessing whether ground is workable, and for motorhome or caravan pitch suitability.</td></tr>
|
||
<tr><td><strong>Concrete °C</strong></td><td>Estimated temperature of sun-exposed urban paving. Concrete absorbs more solar energy than grass and cannot cool itself through evaporation — surface temps can run 15–25 °C above air temperature on sunny days.</td></tr>
|
||
<tr><td><strong>Vehicle °C</strong></td><td>Estimated ambient cabin temperature inside a sealed, parked vehicle — adjusted for your chosen vehicle type. Values above 35 °C are dangerous for children and pets; above 45 °C potentially fatal within minutes.</td></tr>
|
||
<tr><td><strong>Indoors °C</strong></td><td>Estimated temperature inside a building with windows closed and no active cooling. Select your building type from the dropdown — brick, modern insulated, Victorian terrace, stone cottage, timber frame, top-floor flat, or conservatory. Each type has its own insulation, retained warmth, thermal mass, and glazing characteristics. Indoor peak typically lags the outdoor peak by 2–4 hours due to thermal mass.</td></tr>
|
||
<tr><td><strong>Managed °C</strong></td><td>The same building model with two interventions applied: curtains closed by day to block solar gain, and windows opened whenever outdoor air is cooler than inside. Toggle with the Managed tick next to the building dropdown. Shows how much passive cooling can reduce indoor heat compared to doing nothing.</td></tr>
|
||
</tbody>
|
||
</table>
|
||
|
||
<h2>Urban heat: concrete surface temperature</h2>
|
||
<p>
|
||
The UTCI standard was developed with a natural grass surface as its reference ground — the
|
||
assumption being that you're standing in a park or open field. In a city, that assumption
|
||
breaks down. Concrete and tarmac absorb more solar energy than grass, and unlike grass they
|
||
cannot cool themselves through evaporation. On a sunny summer afternoon, exposed concrete
|
||
can run 15–25 °C hotter than the surrounding air.
|
||
</p>
|
||
<p>
|
||
SunScope's <strong>Concrete surface</strong> column estimates the temperature of sun-exposed
|
||
urban paving using an energy-balance model that accounts for how much solar radiation the
|
||
surface absorbs, how efficiently the air above it carries that heat away (which depends on
|
||
wind speed), and the reflective properties of typical urban concrete. The result gives you
|
||
a sense of the contact heat stress you'd experience sitting, standing, or walking barefoot
|
||
on city surfaces — something the standard UTCI value alone won't tell you.
|
||
</p>
|
||
<p>
|
||
The column is enabled by default in the <strong>Places → Urban</strong> variant and colour-coded:
|
||
values above 30 °C are shown in amber, above 40 °C in red.
|
||
</p>
|
||
|
||
<h2>Vehicle interior temperature</h2>
|
||
<p>
|
||
A sealed, parked vehicle heats up far faster than most people expect. SunScope's
|
||
<strong>Vehicle</strong> column models the ambient cabin air temperature experienced by an
|
||
occupant who is seated out of direct sunlight — the classic scenario of a child or pet left
|
||
inside a parked car.
|
||
</p>
|
||
<p>
|
||
The calculation combines two physical processes. The first is <strong>body panel
|
||
conduction</strong>: body panels absorb solar radiation and conduct heat into the cabin
|
||
regardless of the sun's position in the sky. Thin metal car panels pass much more of this
|
||
heat through than the insulated sandwich panels used in many motorhomes and caravans. This
|
||
is the slow, relentless background heat that builds even on overcast days. The second is
|
||
<strong>side-window solar gain</strong>: when the sun is at an elevation where its rays
|
||
cut through the side glass rather than striking the roof or reflecting off at a shallow
|
||
angle, additional heat enters the cabin. Because the occupant is modelled as sitting out of
|
||
the direct beam, this energy goes into raising the ambient cabin air temperature rather than
|
||
heating the person directly — which is precisely what makes it so dangerous. The air around
|
||
you heats up steadily while you remain unaware of how hot the environment has become.
|
||
</p>
|
||
<p>
|
||
Wind speed has almost no effect on a sealed vehicle and is not factored in unless the
|
||
Ventilation toggle is enabled. For cars, the figure represents the cabin temperature after
|
||
roughly 45–60 minutes of parking. For motorhomes and caravans, the model allows for lower
|
||
heat gain, slower response from insulated panels, and retained occupied-space warmth, so
|
||
the estimate stays much closer to the real living-space temperature on cool or moderate
|
||
sunny days. Values above 35 °C are shown in amber (dangerous for children and pets);
|
||
above 45 °C in red (potentially fatal within minutes).
|
||
</p>
|
||
|
||
<h2>Reading the stress bands</h2>
|
||
<p>SunScope maps every UTCI+P value to a thermal stress band so you can read conditions at a glance:</p>
|
||
|
||
<table class="stress-table">
|
||
<thead>
|
||
<tr><th>UTCI range</th><th>Band</th><th>What it means outdoors</th></tr>
|
||
</thead>
|
||
<tbody>
|
||
<tr><td><span class="swatch" style="background:#23408f"></span>Below −27 °C</td><td>Polar</td><td>Survivable only with expedition-grade kit; do not go outside unprepared</td></tr>
|
||
<tr><td><span class="swatch" style="background:#3f73c4"></span>−27 to −13 °C</td><td>Arctic</td><td>Very strong cold stress; full winter protection needed</td></tr>
|
||
<tr><td><span class="swatch" style="background:#7eb0e0"></span>−13 to 0 °C</td><td>Freezing</td><td>Strong cold stress; warm layers essential</td></tr>
|
||
<tr><td><span class="swatch" style="background:#bcd9ec"></span>0 to 9 °C</td><td>Cold</td><td>Moderate cold stress; coat and gloves advised</td></tr>
|
||
<tr><td><span class="swatch" style="background:#c8dcc0"></span>9 to 18 °C</td><td>Chilled</td><td>Slight cold stress; comfortable with a light jacket</td></tr>
|
||
<tr><td><span class="swatch" style="background:#4a8a3a"></span>18 to 26 °C</td><td>Comfortable</td><td>No thermal stress; ideal outdoor conditions</td></tr>
|
||
<tr><td><span class="swatch" style="background:#f5c842"></span>26 to 32 °C</td><td>Mod heat</td><td>Moderate heat stress; stay hydrated</td></tr>
|
||
<tr><td><span class="swatch" style="background:#f5821f"></span>32 to 38 °C</td><td>Strong heat</td><td>Strong heat stress; limit strenuous activity</td></tr>
|
||
<tr><td><span class="swatch" style="background:#e03030"></span>38 to 46 °C</td><td>V. strong heat</td><td>Very strong heat stress; seek shade and cool fluids</td></tr>
|
||
<tr><td><span class="swatch" style="background:#8b1a1a"></span>Above 46 °C</td><td>Extreme heat</td><td>Extreme heat stress; dangerous for outdoor exposure</td></tr>
|
||
</tbody>
|
||
</table>
|
||
|
||
<h2>Have a question?</h2>
|
||
|
||
<p>
|
||
The full set of frequently asked questions — covering UTCI, UV safety, car heat, air quality, pollen, home cooling, farming, and more — lives on the dedicated <a href="./faq.html">FAQ page</a>.
|
||
</p>
|
||
|
||
<h2>Get in touch</h2>
|
||
<p>
|
||
SunScope is an independent project. If you have feedback, spotted a bug, or are interested in
|
||
using SunScope data for your business or website, feel free to reach out via
|
||
<a href="mailto:hello@sunscope.net">hello@sunscope.net</a>.
|
||
</p>
|
||
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