UV Index Today in McHenry County, Illinois (IL)

Tuesday, April 7, 2026 - 3:47 AM CDT (GMT-5)

The average maximum UV Index today across 53 locations in McHenry County, Illinois (IL), is 5.5. The highest projected maximum is 5.5 in Algonquin at 1:00 PM CDT, while the lowest projected maximum is 5.5 in Algonquin at 1:00 PM CDT.

Tomorrow, the average maximum UV Index across those same locations is expected to be 5.3. The highest projected maximum is 5.6 in Gilberts at 1:00 PM CDT, and the lowest projected maximum is 4.9 in Chemung at 12:00 PM CDT.

17 County Subdivisions in McHenry County, Illinois (IL)

Maximum UV Index Today

36 Places in McHenry County, Illinois (IL)

Maximum UV Index Today