As of 1:16 PM PDT on July 15, 2025, out of 50 cities in Contra Costa County, CA in our database, 41 cities (82%) have a UV Index reading of Very High, while 9 cities (18%) have a UV Index reading of Extreme. The city with the highest UV Index reading right now is San Ramon, CA with a reading of 10.5.
Over the next 24 hours, the highest UV Index reading in Contra Costa County, CA is expected to be 10.5 in San Ramon between 1:00 PM - 2:00 PM PDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |