As of 10:49 PM PDT on October 28, 2025, all 1 cities in San Francisco County, CA in our database have a UV Index reading of 0, indicating no radiation from the sun.
Over the next 24 hours, the highest UV Index reading in San Francisco County, CA is expected to be 4.2 in San Francisco between 1:00 PM - 2:00 PM PDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |