Radon zones in Illinois
Zone 1: 56, Zone 2: 43, Zone 3: 3. A zone is an area estimate; EPA says all homes should be tested.
- Adams County Zone 1
- Alexander County Zone 3
- Bond County Zone 2
- Boone County Zone 1
- Brown County Zone 1
- Bureau County Zone 1
- Calhoun County Zone 1
- Carroll County Zone 1
- Cass County Zone 1
- Champaign County Zone 1
- Christian County Zone 2
- Clark County Zone 2
- Clay County Zone 2
- Clinton County Zone 2
- Coles County Zone 1
- Cook County Zone 2
- Crawford County Zone 2
- Cumberland County Zone 2
- DeKalb County Zone 1
- De Witt County Zone 1
- Douglas County Zone 1
- DuPage County Zone 2
- Edgar County Zone 1
- Edwards County Zone 2
- Effingham County Zone 2
- Fayette County Zone 2
- Ford County Zone 1
- Franklin County Zone 2
- Fulton County Zone 1
- Gallatin County Zone 2
- Greene County Zone 1
- Grundy County Zone 1
- Hamilton County Zone 2
- Hancock County Zone 1
- Hardin County Zone 2
- Henderson County Zone 1
- Henry County Zone 1
- Iroquois County Zone 1
- Jackson County Zone 2
- Jasper County Zone 2
- Jefferson County Zone 2
- Jersey County Zone 1
- Jo Daviess County Zone 1
- Johnson County Zone 2
- Kane County Zone 1
- Kankakee County Zone 2
- Kendall County Zone 1
- Knox County Zone 1
- Lake County Zone 2
- LaSalle County Zone 1
- Lawrence County Zone 2
- Lee County Zone 1
- Livingston County Zone 1
- Logan County Zone 1
- McDonough County Zone 1
- McHenry County Zone 2
- McLean County Zone 1
- Macon County Zone 1
- Macoupin County Zone 2
- Madison County Zone 2
- Marion County Zone 2
- Marshall County Zone 1
- Mason County Zone 1
- Massac County Zone 3
- Menard County Zone 1
- Mercer County Zone 1
- Monroe County Zone 2
- Montgomery County Zone 2
- Morgan County Zone 1
- Moultrie County Zone 1
- Ogle County Zone 1
- Peoria County Zone 1
- Perry County Zone 2
- Piatt County Zone 1
- Pike County Zone 1
- Pope County Zone 2
- Pulaski County Zone 3
- Putnam County Zone 1
- Randolph County Zone 2
- Richland County Zone 2
- Rock Island County Zone 1
- St. Clair County Zone 2
- Saline County Zone 2
- Sangamon County Zone 1
- Schuyler County Zone 1
- Scott County Zone 1
- Shelby County Zone 2
- Stark County Zone 1
- Stephenson County Zone 1
- Tazewell County Zone 1
- Union County Zone 2
- Vermilion County Zone 1
- Wabash County Zone 2
- Warren County Zone 1
- Washington County Zone 2
- Wayne County Zone 2
- White County Zone 2
- Whiteside County Zone 1
- Will County Zone 2
- Williamson County Zone 2
- Winnebago County Zone 1
- Woodford County Zone 1
County not listed? See what we left out and why. Leave your email to hear if this data changes.