As of 10:26 PM PDT on September 22, 2025, all 2 cities in San Juan County, WA 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 Juan County, WA is expected to be 4.6 in Friday Harbor 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 |