UV and skin index / San Francisco
UV index in San Francisco right now
UV 0 · Low UV: air 58°F, feels like 58°F, least sun 17:00–19:00.
- Low UV: no protection needed for most skin; daily SPF is still the dermatologists' habit
UV is MET Norway's clear-sky value with the hour's cloud taken out; the label is the WHO category. Weather, not advice: fair skin, children and some medicines burn sooner.
Next 24 hours
| Time | Air | UV index |
|---|---|---|
| 1:00 PM | 58°F | 0 |
| 4:00 PM | 58°F | 0 |
| 7:00 PM | 61°F | 0.7 |
| 10:00 PM | 63°F | 0.8 |
| 1:00 AM | 60°F | 0.1 |
| 4:00 AM | 57°F | 0 |
| 7:00 AM | 58°F | 0 |
| 10:00 AM | 57°F | 0 |
Weather data: MET Norway · updated 1:55 PM · refreshes every 15 minutes
Skin weather in San Francisco
San Francisco is mild most of the year; the index mainly moves with summer UV and winter dryness. The hour-by-hour table shows when the UV is lowest if you want to be outside.
How the index works
MET Norway gives a clear-sky UV index for each hour; cloud takes up to 70% of it away, so the number here is for the sky you have. The WHO categories: low 0–2, moderate 3–5 (sunscreen for time outside), high 6–7 (sunscreen on every uncovered part, reapply), very high 8–10 and extreme 11+ (shade and cover between 10 and 4). Dry air under 30% humidity and cold wind are the other two things the day does to skin.