As of 2:07 PM PDT on May 20, 2026, all 2 cities in Columbia County, WA in our database have a UV Index reading of High. The city with the highest UV Index reading right now is Dayton, WA with a reading of 6.3.
Over the next 24 hours, the highest UV Index reading in Columbia County, WA is expected to be 7.5 in Dayton 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 |