UV Index Today in St. Clair County, Illinois (IL)

The average maximum UV Index today across 50 locations in St. Clair County, Illinois (IL), is 3.3. The highest projected maximum is 4.6 in Belleville at 11:00 AM CDT, while the lowest projected maximum is 1.6 in St. Louis at 2:00 PM CDT.

Tomorrow, the average maximum UV Index across those same locations is expected to be 7.9. The highest projected maximum is 8.4 in Belleville at 1:00 PM CDT, and the lowest projected maximum is 7.1 in O'Fallon at 1:00 PM CDT.