As of 9:50 AM PDT on June 27, 2025, all 33 cities in San Mateo County, CA in our database have a UV Index reading of Moderate. The city with the highest UV Index reading right now is San Mateo, CA with a reading of 2.8.
Over the next 24 hours, the highest UV Index reading in San Mateo County, CA is expected to be 10 in Daly City between 1:00 PM - 2:00 PM PDT today.
Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
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Color | |||||
Risk | Low | Moderate | High | Very High | Extreme |