McHenry County, IL: Current UV Index and Hourly Forecast

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As of 2:25 PM CDT on April 1, 2025, all 40 cities in McHenry County, IL in our database have a UV Index reading of Moderate. The city with the highest UV Index reading right now is Crystal Lake, IL with a reading of 3.1.

Over the next 24 hours, the highest UV Index reading in McHenry County, IL is expected to be 3.1 in Crystal Lake between 2:00 PM - 3:00 PM CDT today.

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Current UV Index in Cities in McHenry County, IL

• Alden - 3
• Algonquin - 3.1
• Big Foot Prairie - 3
• Bull Valley - 3.1
• Burtons Bridge - 3.1
• Cary - 3.1
• Chemung - 3
• Coral - 3.1
• Crystal Lake - 3.1
• Fox River Grove - 3.1
• Franklinville - 3.1
• Greenwood - 3
• Harmony - 3.1
• Hartland - 3.1
• Harvard - 3
• Hebron - 3
• Holiday Hills - 3.1
• Huntley - 3.1
• Island Lake - 3.1
• Johnsburg - 3
• Lake in the Hills - 3.1
• Lakemoor - 3.1
• Lakewood - 3.1
• Lawrence - 3
• Marengo - 3.1
• McCullom Lake - 3.1
• McHenry - 3.1
• Oakwood Hills - 3.1
• Pistakee Highlands - 3
• Prairie Grove - 3.1
• Richmond - 3
• Ridgefield - 3.1
• Riley - 3.1
• Ringwood - 3
• Solon Mills - 3
• Spring Grove - 3
• Trout Valley - 3.1
• Union - 3.1
• Wonder Lake - 3
• Woodstock - 3.1