As of 10:15 AM CDT on July 10, 2026, all 3 cities in Sully County, SD in our database have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Onida, SD with a reading of 3.5.
Over the next 24 hours, the highest UV Index reading in Sully County, SD is expected to be 8.7 in Onida between 2:00 PM - 3:00 PM CDT today.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |