St. Clair County, IL: Current UV Index and Hourly Forecast

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As of 12:52 PM CDT on June 27, 2026, out of 32 cities in St. Clair County, IL in our database, 22 cities (69%) have a UV Index reading of Very High, while 10 cities (31%) have a UV Index reading of High. The city with the highest UV Index reading right now is New Athens, IL with a reading of 7.8.

Over the next 24 hours, the highest UV Index reading in St. Clair County, IL is expected to be 8.1 in Mascoutah between 11:00 AM - 12:00 PM CDT tomorrow.

Search Cities in St. Clair County, IL

Current UV Index in Cities in St. Clair County, IL

• Alorton - 7.5
• Belleville - 7.5
• Brooklyn - 7.6
• Cahokia - 7.5
• Caseyville - 7
• Centreville - 7.5
• Darmstadt - 7.8
• Dupo - 7.5
• East Carondelet - 7.5
• East St. Louis - 7.5
• Fairmont City - 7
• Fairview Heights - 7.5
• Fayetteville - 7.3
• Floraville - 7.5
• Freeburg - 7.5
• Lebanon - 7.3
• Lenzburg - 7.8
• Marissa - 7.8
• Mascoutah - 7.3
• Millstadt - 7.5
• New Athens - 7.8
• O'Fallon - 7.5
• Paderborn - 6.8
• Rentchler - 7.3
• Sauget - 7.5
• Scott AFB - 7.3
• Shiloh - 7.5
• Smithton - 7.5
• St. Libory - 7.8
• Summerfield - 7.3
• Swansea - 7.5
• Washington Park - 7