As of 2:38 PM MST on December 21, 2025, all 237 cities in Idaho in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is St. Charles, ID with a reading of 1.1.
Over the next 24 hours, the highest UV Index reading in Idaho is expected to be 1.7 in Lost River between 12:00 PM - 1:00 PM MST tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |