Tweaked shade calc
Updated About and FAQ sections
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<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>About SunScope · The True Temperature</title>
<meta name="description" content="SunScope uses the Universal Thermal Climate Index (UTCI) and its original SunSoak index to show how the weather will really feel on your body — including rain, snow, wind, solar radiation, environment type, air quality, pollen, and visibility." />
<meta name="description" content="SunScope uses the Universal Thermal Climate Index (UTCI) and its original SunSoak index to show how the weather will really feel on your body — rain, snow, wind, solar radiation, Solar Model surroundings, air quality, pollen, and visibility." />
<meta name="robots" content="index, follow" />
<link rel="canonical" href="https://sunscope.net/about.html" />
<!-- Open Graph -->
<meta property="og:title" content="About SunScope · The True Temperature" />
<meta property="og:description" content="What is UTCI? How does SunSoak work? Learn how SunScope calculates felt temperature across different environments — forest, alpine, beach, desert and more — plus urban heat, vehicle temperatures, and an honest outdoor comfort forecast." />
<meta property="og:description" content="What is UTCI? How does SunSoak work? An overview of how SunScope calculates felt temperature across different surroundings — plus vehicle, indoor and concrete temperatures, air quality, and an honest outdoor comfort forecast." />
<meta property="og:url" content="https://sunscope.net/about.html" />
<meta property="og:type" content="website" />
<meta property="og:image" content="https://sunscope.net/og-image.png" />
@@ -18,7 +18,7 @@
<!-- Twitter Card -->
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:title" content="About SunScope · The True Temperature" />
<meta name="twitter:description" content="What is UTCI? How does SunSoak work? Learn how SunScope calculates felt temperature across different environments — forest, alpine, beach, desert and more — plus urban heat, vehicle temperatures, and an honest outdoor comfort forecast." />
<meta name="twitter:description" content="What is UTCI? How does SunSoak work? An overview of how SunScope calculates felt temperature across different surroundings, plus vehicle, indoor and concrete temperatures." />
<meta name="twitter:image" content="https://sunscope.net/og-image.png" />
<link rel="icon" type="image/svg+xml" href="./favicon.svg" />
@@ -48,7 +48,7 @@
"@type": "WebSite",
"name": "SunScope",
"url": "https://sunscope.net",
"description": "SunScope is a free outdoor thermal comfort forecast using the Universal Thermal Climate Index (UTCI) and the SunSoak index — combining precipitation, environment modifiers, and mean radiant temperature into a single honest felt-temperature number."
"description": "SunScope is a free outdoor thermal comfort forecast using the Universal Thermal Climate Index (UTCI) and the SunSoak index — combining precipitation, Solar Model surroundings, and mean radiant temperature into a single honest felt-temperature number."
}
</script>
</head>
@@ -59,7 +59,18 @@
<a href="./index.html" class="logo"><span class="logo-sun">Sun</span><svg class="logo-icon" viewBox="0 0 174 173" aria-hidden="true" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:1.5;"><g transform="matrix(0.986226,0,0,0.986226,-585.724252,-110.041209)"><clipPath id="ss-clip-ab"><circle cx="681.9838" cy="199.4502" r="83.2987"/></clipPath><g clip-path="url(#ss-clip-ab)"><g transform="matrix(0.948836,0,0,0.948836,19.787839,-2.49381)"><path d="M666.992,233.0768C666.3949,230.6581 666.1785,228.6317 666.1785,226.0296C666.1785,208.6786 680.2653,194.5919 697.6163,194.5919C714.9672,194.5919 729.054,208.6786 729.054,226.0296C729.054,228.4125 728.9892,230.9346 728.4859,233.1663" fill="none" stroke="#c8922a" stroke-width="7.48"/></g><g transform="matrix(0.520349,0,0,0.520349,304.766642,64.226716)"><path d="M724.9315,291.8131C777.359,291.8131 826.5862,305.6245 869.1698,329.8044" fill="none" stroke="currentColor" stroke-width="13.64"/></g><g transform="matrix(0.520349,0,0,0.520349,304.766642,64.226716)"><path d="M580.8436,329.719C623.3927,305.592 672.5657,291.8131 724.9315,291.8131" fill="none" stroke="currentColor" stroke-width="13.64"/></g></g><circle cx="681.9838" cy="199.4502" r="83.2987" fill="none" stroke="currentColor" stroke-width="9.13"/></g></svg><span class="logo-scope">Scope</span></a>
<div class="nav-links" id="nav-drawer">
<a href="./index.html">Forecast</a>
<a href="./about.html" class="active">About</a>
<div class="nav-dropdown">
<a href="./about.html" class="nav-dropdown-toggle active">About<span class="caret"></span></a>
<div class="nav-dropdown-menu">
<a href="./about.html" class="active">Overview</a>
<a href="./sunsoak.html">SunSoak &amp; the science</a>
<a href="./profiles.html">Forecast profiles</a>
<a href="./columns.html">Column reference</a>
<a href="./temperatures.html">Derived temperatures</a>
<a href="./features.html">On-screen features</a>
<a href="./stress-bands.html">Stress bands</a>
</div>
</div>
<a href="./faq.html">FAQ</a>
<a href="https://billing.stripe.com/p/login/9B63cw7vl8k15Ei9DQd7q00" target="_blank" rel="noopener noreferrer">Account</a>
</div>
@@ -95,521 +106,75 @@
The core calculation is the <strong>Universal Thermal Climate Index (UTCI)</strong>, a
peer-reviewed biometeorological standard developed by
<a href="https://utci.org/" target="_blank" rel="noopener noreferrer">Bröde et al. (2012)</a>
and used globally in heat-health warning systems and urban planning. On top of that, SunScope
builds its own <strong>SunSoak</strong> index — because UTCI alone doesn't account for the full
picture of where you actually are and what the weather is actually doing to you. SunSoak layers
three extra dimensions on top of UTCI: a <strong>rain and snow penalty</strong> for the chill of
wet clothing and skin; an <strong>environment modifier</strong> that adjusts the solar and
thermal load for your surroundings (forest canopy, alpine altitude, lakeside glare, shaded
riverbank, desert ground heat); and the full radiant heat absorbed from surrounding surfaces.
One number that honestly answers: <em>what will my body actually feel out there?</em>
and used globally in heat-health warning systems. On top of that, SunScope builds its own
<strong>SunSoak</strong> index — layering a rain and snow penalty, a <strong>Solar Model</strong>
that adjusts the solar and thermal load for your surroundings, and the full radiant heat absorbed
from surrounding surfaces. One number that honestly answers: <em>what will my body actually feel
out there?</em>
</p>
<p>
Forecast data is sourced in real time from <strong>Open-Meteo</strong>, a free and open-source
weather API drawing on ECMWF and national meteorological services. The forecast refreshes
automatically every five minutes and is available for any location worldwide.
weather API drawing on ECMWF and national meteorological services, with air quality, visibility,
and pollen from the Copernicus CAMS forecast. The forecast refreshes automatically every five
minutes and is available for any location worldwide.
</p>
<h2>What else does SunScope calculate?</h2>
<h2>Explore the details</h2>
<p>
SunScope goes far beyond a single felt-temperature number. Depending on the profile you choose,
it can calculate and display a wide range of derived quantities, each built on the same
per-hour weather data:
</p>
<p>
<strong>Vehicle interior temperature.</strong> A physics-based model estimates how hot a sealed,
parked vehicle gets over time — combining heat conducted through the roof and body panels with
direct solar gain through the side windows. You can select your vehicle type (car, MPV, SUV,
motorhome, or caravan), each of which has its own albedo, glazing area, and insulation
characteristics. A <em>Windows open</em> toggle switches to a ventilated model where convective
loss is roughly five times higher, dramatically reducing cabin heat build-up — mirroring the
real-world effect of cracking the windows.
</p>
<p>
<strong>Indoor temperature.</strong> The <em>Indoors</em> column estimates the temperature
inside a building with windows closed and no air conditioning, simulating retained warmth,
window solar gain, internal gains, and thermal mass hour by hour. You choose your building type from a dropdown
— brick, modern insulated, Victorian terrace, stone cottage, timber frame, top-floor flat, or
conservatory — and the physics model adjusts accordingly. Each type has its own insulation
level, thermal mass, retained warmth, and glazing characteristics, so a stone cottage and a conservatory behave
very differently on a hot day. The model now lags toward a realistic hourly target rather
than repeatedly adding solar heat, so indoor temperatures typically peak 24 hours after the outdoor
peak, which is why a house can still feel stifling at 10 pm on a summer day. Tick
<em>Managed</em> alongside the dropdown to switch to the heatwave-advice model: curtains
closed by day to cut solar gain, windows opened whenever outdoor air is cooler than inside.
</p>
<p>
<strong>Urban concrete surface temperature.</strong> Concrete and tarmac absorb far more solar
energy than grass, and unlike grass they have no evaporative cooling. On a sunny summer
afternoon, exposed paving can run 1525 °C hotter than the surrounding air. SunScope models
this using a surface energy balance approach that accounts for solar absorption, surface
emissivity, and convective cooling by wind.
</p>
<p>
<strong>UV and sunburn.</strong> SunScope splits the solar UV spectrum into UV-A and UV-B
components. The burn-time column estimates how long before you reach one Minimal Erythemal
Dose (the clinical threshold for sunburn) based on the UV index and your Fitzpatrick skin type
— selected from a dropdown in the column bar.
</p>
<p>
<strong>Soil temperature and moisture.</strong> Surface and 6 cm soil temperatures are shown for
agricultural and outdoor-work planning. Soil moisture indicates whether the ground is workable
or saturated — particularly useful for motorhome and caravan pitching.
</p>
<p>
<strong>Air quality, visibility, and pollen.</strong> Three atmospheric columns sit together
after cloud cover in the table. <em>Visibility</em> shows horizontal visibility in kilometres,
sourced from the CAMS model — values below 1 km indicate fog, below 10 km suggest mist or
pollution haze. <em>AQI</em> shows the European Air Quality Index (0100+), combining PM2.5,
PM10, ozone, nitrogen dioxide, and sulphur dioxide, with colour-coded bands from Good to
Hazardous. <em>Pollen</em> shows concentration in grains per cubic metre for a selectable
pollen type — choose from total pollen, grass, birch, alder, mugwort, olive, or ragweed — with
Low / Moderate / High / Very High labels. All three are sourced from the Copernicus CAMS
air quality forecast.
</p>
<p>
<strong>The sky scope.</strong> The large circular visualisation at the top of the page shows
the sky conditions for the currently selected hour. The sky colour smoothly interpolates through
a full set of elevation-keyed gradients — from deep pre-dawn navy through golden sunrise, bright
midday blue, warm sunset amber, and back to night — with a sun disc whose glow radius and
intensity scale with the actual shortwave radiation at that moment. It refreshes automatically
alongside the forecast.
</p>
<p>
<strong>Day strip weather and temperatures.</strong> Each day tab in the date selector shows the
day's forecast at a glance: a weather icon representing the dominant daytime conditions (sun,
cloud variants, or precipitation), plus the day's high and low SunSoak felt temperatures in
warm and cool colours. The icon uses the actual daytime solar elevation and cloud category data
so it reflects the real character of the day rather than a generic symbol.
</p>
<p>
<strong>Weather event banners and popups.</strong> When notable weather conditions are forecast
— such as a frost, strong winds, fog, or a heat event — a banner appears above the forecast
table with a brief alert. Tapping or clicking the event icon opens a detailed description
popup explaining what the condition means and what to watch out for.
</p>
<p>
<strong>What's Coming — cosmic events almanac.</strong> A 🔭 panel below the forecast table
shows upcoming astronomical events for your location over the next 90 days: meteor showers,
lunar and solar eclipses, planetary conjunctions, and oppositions. Each entry shows the event
name, peak date, a countdown, a short description, and a visibility note where the event is
better from a particular hemisphere or location. When a cosmic event is currently active,
it also appears as a banner above the forecast table alongside the weather alerts.
</p>
<h2>What is SunSoak?</h2>
<p>
Standard UTCI is calculated assuming open, unshaded conditions with no precipitation — it tells
you how the wind and sun affect your body, but not the full picture of where you actually are or
what the weather is actively doing to you. <strong>SunSoak</strong> fills those gaps with three
layers of original calculation stacked on top of the UTCI foundation.
</p>
<p>
<strong>The precipitation penalty.</strong> Rain and snow are not in UTCI. The soak-factor
formula adds an original penalty based on rain intensity, snowfall rate, and wind speed —
reflecting the extra chill of wet clothing and skin. Light drizzle (under 1 mm/hr) reduces the
felt temperature by roughly 12 °C. Heavy rain combined with strong wind can push it down by
78 °C. Snowfall carries an additional penalty on top.
</p>
<p>
<strong>The environment modifier.</strong> UTCI assumes you are standing in the open. SunSoak
adjusts the solar radiation load and air temperature for six distinct environments, selectable
from a dropdown on the SunSoak column: <em>Open / Exposed</em> (the UTCI default);
<em>Forest / Woodland</em> (canopy reduces direct radiation by ~85%, evapotranspiration
cooling lowers apparent air temperature); <em>High Altitude / Alpine</em> (thinner atmosphere
increases radiation dose by ~15% at 2,000 m); <em>Beach / Lakeside</em> (water and sand
reflection increases effective solar load); <em>River / Riverbank</em> (partial canopy and
strong evaporative cooling from the water surface); and <em>Desert / Arid</em> (extreme
radiation from high-albedo ground, with significant ground-level heat adding to felt
temperature). Selecting a Place or Activity profile automatically sets the most appropriate
environment for that context — but you can always override it manually.
</p>
<p>
<strong>Mean radiant temperature.</strong> The full radiant heat load from surrounding surfaces
— ground, walls, sky, and direct sun — is calculated as Mean Radiant Temperature (Tmrt) and
fed into the UTCI polynomial. On a sunny day this alone can add 2030 °C to the felt
temperature compared to a shaded reading.
</p>
<h2>Forecast profiles</h2>
<p>
SunScope organises its columns into <strong>profiles</strong> — curated sets of data tailored
to different activities and use cases. Rather than showing every column at once, each profile
surfaces the information that actually matters for that situation. You can switch between
<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.
This guide is split into focused sections. Pick the one you're after — or work through them in
order for the full picture of how SunScope turns raw weather data into an honest felt-temperature
forecast.
</p>
<div class="profile-block">
<p class="profile-name">🌡️ Basic</p>
<p class="profile-name"><a href="./sunsoak.html">🌡️ SunSoak &amp; the science →</a></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>SunSoak</strong> — the
felt-temperature index that combines sun, wind, humidity, rain, and your environment into a
single honest number. The right starting point for most people most of the time.
What SunSoak is and how it's built on top of UTCI — the precipitation penalty, the Solar Model
that adapts to eight different surroundings, and mean radiant temperature from the sun and
surfaces around you.
</p>
</div>
<div class="profile-block">
<p class="profile-name">🏠 Home</p>
<p class="profile-name"><a href="./profiles.html">📋 Forecast profiles →</a></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 24 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.
The curated column sets — Basic, Home, Vehicle, Temps, Show All and Custom — plus the Places,
Activities and Work dropdowns, each tailored to a specific situation.
</p>
</div>
<div class="profile-block">
<p class="profile-name">🚗 Vehicle</p>
<p class="profile-name"><a href="./columns.html">📊 Column reference →</a></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 2535 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>SunSoak</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 40% 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>SunSoak</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>SunSoak</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>SunSoak</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>SunSoak</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>SunSoak</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 40% 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>SunSoak</strong> for wet-weather comfort, and <strong>precipitation</strong>.
Every column in the forecast table explained in plain language, from Air and Shade Air through
to Lightning Potential, air quality, pollen, and SunSoak.
</p>
</div>
<div class="profile-block">
<p class="profile-name">🎯 Activities</p>
<p class="profile-name"><a href="./temperatures.html">🚗 Derived temperatures →</a></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 organic growers first, but just as useful for any
farmer, smallholder, or market gardener working the land. Decision-making on the land 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 windows to apply foliar feeds
and organic-approved sprays without drift onto buffer zones or watercourses),
<strong>cloud cover</strong> and <strong>sun elevation</strong> for light levels,
<strong>SunSoak</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 foliar-feed timing), 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>SunSoak</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>SunSoak</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>SunSoak</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>SunSoak</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>SunSoak</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>SunSoak</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>SunSoak</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>SunSoak</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.
The physics-based temperature models: how hot a parked vehicle gets, how warm a building stays
indoors without air conditioning, and how sun-baked urban concrete becomes.
</p>
</div>
<div class="profile-block">
<p class="profile-name">🌡️ Temps · Extra</p>
<p class="profile-name"><a href="./features.html">🔭 On-screen features →</a></p>
<p>
A comparison view that brings all temperature-derived columns into one place:
<strong>air temperature</strong>, <strong>SunSoak felt temperature</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.
The sky scope, day-strip weather icons, weather-event banners and popups, and the "What's
Coming" cosmic events almanac.
</p>
</div>
<div class="profile-block">
<p class="profile-name">⚙️ Custom · Extra</p>
<p class="profile-name"><a href="./stress-bands.html">🎨 Reading the stress bands →</a></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 SunSoak. Build
exactly the view that suits your situation.
How SunScope maps every SunSoak value to a colour-coded thermal stress band, from Polar cold
through Comfortable to Extreme heat.
</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 (0100+), combining PM2.5, PM10, ozone, nitrogen dioxide, and sulphur dioxide. 020 = Good; 2040 = Fair; 4060 = Moderate; 6080 = Poor; 80100 = 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 = &lt;10; Moderate = 1050; High = 50200; 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 2030 °C on a sunny day; this is why shade feels so much cooler.</td></tr>
<tr><td><strong>UTCIAir 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>SunSoak °C</strong></td><td>SunScope's signature felt-temperature index. Starts from UTCI then adds three layers: a rain and snow penalty (wet clothing can drop felt temperature by up to 8 °C), an environment modifier for where you actually are (forest, alpine, beach, river, desert), and full mean radiant temperature from surrounding surfaces. The most honest single answer to: what will it actually feel like out there?</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 710 °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>Water saturation of the top 1 cm of soil as a percentage. Above 40% indicates saturated ground; below 20% 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 1525 °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 24 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 1525 °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 4560 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 SunSoak 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>Frequently asked questions</h2>
<p>
Got a specific question &mdash; about UTCI, the SunSoak index, UV and sunburn times, how hot a