As of 8:25 PM MST on December 31, 2025, all 18 cities in Lewis and Clark County, MT 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 Lewis and Clark County, MT is expected to be 1.1 in Helena 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 |