Sun guides
The sun, explained honestly.
Every guide answers a real question with the published science first — then shows how Soleil turns the answer into something your phone just handles for you.
How long can you stay in the sun without burning?
How long you can stay in the sun depends on the UV index and your skin type — from ~10 minutes to a few hours. See the table, the maths, and how to track it live.
Read the guide → UV basicsWhat UV index is safe? The scale, explained properly
UV index below 3 is low risk for most people; 3 and above calls for protection. Full UV scale table, what each level means for your skin, and when to check it.
Read the guide → TanningWhat’s the best UV index for tanning?
Tanning starts from about UV 3. Lower UV means slower colour but lower burn risk; UV 8+ mostly adds damage. The honest dermatology position, plus how to pace exposure.
Read the guide → SunscreenHow often should you reapply sunscreen?
Reapply sunscreen at least every 2 hours — and immediately after swimming, heavy sweating or towel-drying. Why the rule exists, how much to use, and how to never forget.
Read the guide → WellbeingHow much sun do you need for vitamin D?
Around 10–30 minutes of midday sun on forearms a few times a week suffices for lighter skin in summer; darker skin needs longer. Latitude, winter and the honest limits.
Read the guide → UV basicsCan you tan — or burn — through clouds?
Yes — up to 90% of UV passes through light cloud, and broken cloud can even amplify it. Why cloudy-day sunburn is so common and how to check the real UV in seconds.
Read the guide → SkinWhat’s your Fitzpatrick skin type? The 6 types, explained
The Fitzpatrick scale classifies skin I–VI by how it burns and tans. Identify your type with the trait table and see why it changes your sun-protection timing.
Read the guide → FamilyWhat UV index is safe for kids? A parent’s guide
Children need protection from UV 3, and babies under 6 months should stay out of direct sun entirely. Practical family rules — shade, clothing, SPF, reapply timing.
Read the guide → SunscreenWhat does SPF actually mean?
SPF is a lab-measured multiplier of how long skin takes to redden under UVB. SPF 30 filters ~96.7%, SPF 50 ~98% — and real-world application changes everything.
Read the guide → Apple WatchApple Watch “Time in Daylight”, explained
Time in Daylight uses the Apple Watch ambient light sensor to estimate minutes spent in ≥1,000 lux. How it works, where to find it, its limits — and how to pair it with UV.
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