As of 4:47 PM MDT on October 12, 2026, all 13 cities in Yellowstone County, MT in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Acton, MT with a reading of 1.5.
Over the next 24 hours, the highest UV Index reading in Yellowstone County, MT is expected to be 3.5 in Broadview between 12:00 PM - 1:00 PM MDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |