San Francisco California UV Index Today – Hourly Forecast, Burn Time & UV Levels
The UV index in San Francisco California, Usa determines how quickly you will burn based on your Fitzpatrick skin type. Check real-time UV levels, hourly forecasts, and get personalised SPF advice for San Francisco California.
Current UV Conditions in San Francisco California, Usa
The UV index in San Francisco California, Usa averages 7 (High) with peaks reaching 10. Sun protection including SPF 30+, hat, and sunglasses is recommended during midday hours.
- Average UV Index: 7 (High)
- Peak UV Index: 10
- Peak UV Hours: 10:00 AM – 4:00 PM local time
Burn Time by Skin Type in San Francisco California
Estimated time to sunburn at UV 7 in San Francisco California for each Fitzpatrick skin type:
| Skin Type | Burn Time (No SPF) | With SPF 30 | With SPF 50 |
|---|---|---|---|
| Type I (Very Fair) | 14 min | 42 min | 1h 10m |
| Type II (Fair) | 21 min | 1h 3m | 1h 45m |
| Type III (Medium) | 29 min | 1h 27m | 2h 25m |
| Type IV (Olive) | 43 min | 2h 9m | 3h 35m |
| Type V (Brown) | 1h 4m | 3h 12m | 5h 20m |
| Type VI (Dark) | 1h 26m | 4h 18m | 7h 10m |
Source: Fitzpatrick classification system and WHO UV exposure guidelines.
What Does the UV Index in San Francisco California Mean for You?
The UV index measures ultraviolet radiation strength on a scale from 0 to 11+. At UV 7 in San Francisco California, moderate sun protection is essential. Apply SPF 30+ before going outside and reapply every 2 hours. Wear sunglasses and a hat during midday.
How Long Before I Burn in San Francisco California?
At UV 7, a person with very fair skin (Fitzpatrick Type I) may burn in as little as 14 minutes without any sun protection. With SPF 30, that extends to approximately 42 minutes. With SPF 50, safe exposure increases to around 70 minutes. Always reapply sunscreen after swimming, towelling, or heavy sweating.
SPF and Sunscreen Advice for San Francisco California
SPF 30+ sunscreen provides adequate protection for most activities in San Francisco California. Apply generously and reapply every 2 hours. Use SPF 50 for water activities or extended outdoor time.
Best Times for Outdoor Activities in San Francisco California
- Early Morning (6:00–9:00 AM): Lowest UV — ideal for running, cycling, exercise
- Midday (10:00 AM–4:00 PM): Peak UV — limit exposure, seek shade, full protection
- Late Afternoon (4:00–6:00 PM): Decreasing UV — good for sightseeing and beach
- Evening (after 6:00 PM): Negligible UV — safe for all activities
Frequently Asked Questions About UV in San Francisco California
What is the UV index in San Francisco California, Usa today?
The UV index in San Francisco California typically ranges from 5 to 10 depending on time of day, season, and cloud cover. Peak UV occurs between 10 AM and 4 PM local time.
How long can I stay in the sun in San Francisco California without burning?
At UV 7, fair-skinned individuals (Type I) may burn in 14 minutes. Medium skin types (Type III) can tolerate approximately 29 minutes. Apply sunscreen regardless of skin type.
What SPF should I use in San Francisco California?
SPF 30+ is recommended. Reapply every 2 hours. Use SPF 50 for extended outdoor time.
Is San Francisco California safe for people with fair skin?
San Francisco California is safe for fair-skinned visitors with proper protection. Use SPF 30+, a wide-brimmed hat, UV-blocking sunglasses, and seek shade during midday.
Sun Protection Checklist for San Francisco California
- Apply SPF 30+ sunscreen 15 minutes before sun exposure
- Reapply every 2 hours
- Seek shade during 10:00 AM – 4:00 PM
- Wear a wide-brimmed hat and UV-blocking sunglasses
- Choose UPF-rated clothing for maximum protection