As of 11:49 PM CDT on August 7, 2025, all 32 cities in St. Clair County, IL in our database have a UV Index reading of 0, indicating no radiation from the sun.
Over the next 24 hours, the highest UV Index reading in St. Clair County, IL is expected to be 8.8 in New Athens 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 |