Radon Zone Map

All counties

Radon zones in Illinois

Adams CountyIllinois1
Alexander CountyIllinois3
Bond CountyIllinois2
Brown CountyIllinois1
Bureau CountyIllinois1
Carroll CountyIllinois1
Cass CountyIllinois1
Champaign CountyIllinois1
Christian CountyIllinois2
Clark CountyIllinois2
Clay CountyIllinois2
Clinton CountyIllinois2
Coles CountyIllinois1
Cook CountyIllinois2
Crawford CountyIllinois2
Cumberland CountyIllinois2
De Witt CountyIllinois1
Douglas CountyIllinois1
Edgar CountyIllinois1
Effingham CountyIllinois2
Fayette CountyIllinois2
Ford CountyIllinois1
Franklin CountyIllinois2
Fulton CountyIllinois1
Gallatin CountyIllinois2
Greene CountyIllinois1
Grundy CountyIllinois1
Hamilton CountyIllinois2
Hancock CountyIllinois1
Hardin CountyIllinois2
Henderson CountyIllinois1
Henry CountyIllinois1
Iroquois CountyIllinois1
Jackson CountyIllinois2
Jasper CountyIllinois2
Jefferson CountyIllinois2
Jersey CountyIllinois1
Jo Daviess CountyIllinois1
Johnson CountyIllinois2
Kane CountyIllinois1
Kankakee CountyIllinois2
Kendall CountyIllinois1
Knox CountyIllinois1
Lake CountyIllinois2
Lee CountyIllinois1
Livingston CountyIllinois1
Logan CountyIllinois1
Macon CountyIllinois1
Macoupin CountyIllinois2
Madison CountyIllinois2
Marion CountyIllinois2
Marshall CountyIllinois1
Mason CountyIllinois1
McDonough CountyIllinois1
McHenry CountyIllinois2
McLean CountyIllinois1
Menard CountyIllinois1
Mercer CountyIllinois1
Monroe CountyIllinois2
Montgomery CountyIllinois2
Morgan CountyIllinois1
Moultrie CountyIllinois1
Ogle CountyIllinois1
Peoria CountyIllinois1
Perry CountyIllinois2
Piatt CountyIllinois1
Pike CountyIllinois1
Pope CountyIllinois2
Putnam CountyIllinois1
Randolph CountyIllinois2
Richland CountyIllinois2
Rock Island CountyIllinois1
Saline CountyIllinois2
Sangamon CountyIllinois1
Schuyler CountyIllinois1
Scott CountyIllinois1
Shelby CountyIllinois2
St. Clair CountyIllinois2
Stark CountyIllinois1
Stephenson CountyIllinois1
Tazewell CountyIllinois1
Union CountyIllinois2
Warren CountyIllinois1
Washington CountyIllinois2
Wayne CountyIllinois2
White CountyIllinois2
Whiteside CountyIllinois1
Will CountyIllinois2
Williamson CountyIllinois2
Winnebago CountyIllinois1
Woodford CountyIllinois1

Sources

  1. Illinois: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  2. EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  3. Illinois: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  4. EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  5. Illinois: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  6. EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  7. Illinois: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  8. EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  9. Illinois: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  10. EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  11. Illinois: EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026
  12. EPA Map of Radon Zones, US Environmental Protection Agency, checked 1 November 2026

"Secondary" marks a source used only because the official page could not be read.