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 10. The highest projected maximum is 10 in St. Louis at 1:00 PM CDT, while the lowest projected maximum is 9.9 in O'Fallon at 1:00 PM CDT.

Tomorrow, the average maximum UV Index across those same locations is expected to be 9.6. The highest projected maximum is 10 in Centreville at 1:00 PM CDT, and the lowest projected maximum is 9.2 in Belleville at 12:00 PM CDT.