Sunburn Risk Score
One quick read that pulls together everything that decides whether you’ll burn today — the UV index, your skin type, how long you’ll be out, your SPF, altitude, and reflective ground like water, sand, and snow.
Your burn risk
A score near or above 100 means a burn is likely over the time entered. Shorten your time in the sun, add shade and clothing, and reapply sunscreen.
Burn risk is more than the forecast number
The UV index in your weather app is measured for open, flat ground at sea level. Real days aren’t like that. Reflective surfaces throw extra UV up at your face and the underside of your chin; altitude thins the atmosphere that would otherwise absorb some of it; and the same UV that’s harmless in ten minutes becomes a burn over an hour. This score folds those factors together with your own skin type and the protection you’re wearing.
Read it as a nudge, not a verdict. A high score is a prompt to shorten your time in the sun, add a hat and a shirt, find shade at midday, and reapply sunscreen — the same moves that keep every day in the sun on the right side of a burn.
Frequently Asked Questions
What does the score mean?
It compares the time you plan to be outside with the time it would take your skin to burn under the conditions you enter. A score approaching 100 means a burn is likely over that period; under 25 is low risk. It's a planning read, not a guarantee.
Why do water, sand, and snow raise the score?
Because they reflect UV back up at you, adding to what comes straight from the sky. Fresh snow can bounce back the majority of the UV hitting it, sand and water noticeably less — but enough to matter on a beach or a lake. The tool adds a reflectance factor for the surface you choose.
How does altitude change things?
There's less atmosphere to absorb UV the higher you go, so UV strength rises roughly 10% for every 1,000 metres of elevation. That's why you can burn surprisingly fast on a mountain, especially over snow.
Does a high SPF make me safe for the whole day?
No. A higher SPF lowers the score, but only while a full, fresh layer is on your skin — it wears off with time, water, and sweat. Use the score alongside our reapplication timer, and don't treat any number as permission to skip shade and cover-up.
General guidance only, not medical or dermatological advice. This is an estimate of burn risk, not a safety guarantee — see a professional about your own skin.