Illinois

BadAirDays has a full county for each of the 23 places below in Illinois, worked out from the same data for every one of them so the numbers compare directly. Pick yours to see it.

• Adams
• Champaign
• Clark
• Cook
• DuPage
• Effingham
• Hamilton
• Jersey
• Jo Daviess
• Kane
• Lake
• Macon
• Macoupin
• Madison
• McHenry
• McLean
• Peoria
• Randolph
• Rock Island
• Saint Clair
• Sangamon
• Will
• Winnebago