As of 7:05 AM MDT on August 23, 2026, all 11 cities in Big Horn County, WY in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Greybull, WY with a reading of 0.1.
Over the next 24 hours, the highest UV Index reading in Big Horn County, WY is expected to be 8.8 in Hyattville between 1:00 PM - 2:00 PM MDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |