As of 7:41 PM CDT on September 8, 2026, all 3 cities in Sully County, SD in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Onida, SD with a reading of 0.3.
Over the next 24 hours, the highest UV Index reading in Sully County, SD is expected to be 6.2 in Cow Creek between 2:00 PM - 3:00 PM CDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |