As of 3:13 PM CDT on July 22, 2026, all 7 cities in Union County, SD in our database have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Dakota Dunes, SD with a reading of 4.
Over the next 24 hours, the highest UV Index reading in Union County, SD is expected to be 7.7 in Beresford between 1:00 PM - 2:00 PM CDT tomorrow.
| Range | 0 - 2 | 3 - 5 | 6 - 7 | 8 - 10 | 11+ |
|---|---|---|---|---|---|
| Color | |||||
| Risk | Low | Moderate | High | Very High | Extreme |