IL

Storm restoration across Grundy County

Grundy County sits in the northern Illinois severe-weather corridor and is regularly included in National Weather Service tornado watches alongside neighboring counties. The county has experienced EF3-intensity tornadoes - most notably the June 22, 2015 Coal City tornado with 160 mph winds and a 16-mile path that destroyed homes and downed high-tension steel trusses - and historically records tornado events going back to at least 1950, with significant events repeating on roughly decadal cycles. Large hail, derechos, and straight-line wind events are recurring warm-season hazards, and the September 2019 storm system delivered nearly 8 inches of rain in 24 hours to Coal City and Carbon Hill, illustrating the county's flash-flood exposure from intense convective systems. The Kankakee River, which forms part of the county's eastern boundary, creates a distinct winter hazard: major ice-jam flooding events - including a 12-mile jam in January 2024 rated "historic" by Will County officials - can rapidly raise river levels 3 to 5 feet and force evacuations in riverside communities such as South Wilmington.