As of 8:49 AM CDT on August 31, 2025, all 13 cities in Sioux County, IA in our database have a UV Index reading of Low. The city with the highest UV Index reading right now is Rock Valley, IA with a reading of 0.1.
Over the next 24 hours, the highest UV Index reading in Sioux County, IA is expected to be 3.5 in Boyden 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 |