As of 10:01 AM MDT on May 4, 2026, out of 8 cities in Dewey County, SD in our database, 6 cities (75%) have a UV Index reading of Moderate, while 2 cities (25%) have a UV Index reading of Low. The city with the highest UV Index reading right now is Whitehorse, SD with a reading of 2.7.
Over the next 24 hours, the highest UV Index reading in Dewey County, SD is expected to be 4.8 in Whitehorse between 2:00 PM - 3:00 PM MDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |