IL

Storm restoration across Calhoun County

Calhoun County is a narrow peninsula surrounded on three sides by the Mississippi and Illinois Rivers, making it one of Illinois's most flood-vulnerable counties - it has received 10 major federal flood declarations since 1981, with the Great Flood of 1993 and the 2019 river flooding among the most destructive on record. Tornadoes are a documented threat, including an F4 in April 1927 that killed two people near the county seat of Hardin, and additional tornado events in 1958, 1969, 1999, 2006, and 2010, with the county sitting on the northeastern edge of tornado alley where Gulf moisture regularly collides with cold Canadian air. Severe thunderstorms driving large hail and straight-line winds are a recurring warm-season hazard across the southwestern Illinois region, with Illinois ranking 4th nationally in thunderstorm catastrophes from 1949 to 1998. Winter storms bringing ice accumulation and heavy snow periodically isolate the county, which has only two ferry crossings and one bridge as its road connections to surrounding areas.