As of 1:05 PM PDT on April 11, 2026, out of 50 cities in Contra Costa County, CA in our database, 49 cities (98%) have a UV Index reading of High, while 1 city (2%) have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Antioch, CA with a reading of 6.2.
Over the next 24 hours, the highest UV Index reading in Contra Costa County, CA is expected to be 6.2 in Antioch 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 |