As of 11:53 PM PDT on September 15, 2025, all 20 cities in Alameda 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 Alameda County, CA is expected to be 7.4 in Fremont 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 |