Illinois Radon Zone Map
Counties colored by EPA radon zone. Red = Zone 1, Orange = Zone 2, Green = Zone 3.
Highest-Risk Counties
Adams40% above action level
BooneZone 1 — High
BrownZone 1 — High
Bureau62.5% above action level
CalhounZone 1 — High
CarrollZone 1 — High
CassZone 1 — High
Champaign38.5% above action level
Coles66.7% above action level
De WittZone 1 — High
DeKalb35.3% above action level
DouglasZone 1 — High
+44 more
All 102 Counties — By Radon Risk
| County | EPA Zone | Tests | % Above 4 pCi/L |
|---|
| Adams |
High |
15 |
40% |
| Boone |
High |
9 |
— |
| Brown |
High |
— |
— |
| Bureau |
High |
8 |
62.5% |
| Calhoun |
High |
— |
— |
| Carroll |
High |
— |
— |
| Cass |
High |
— |
— |
| Champaign |
High |
26 |
38.5% |
| Coles |
High |
6 |
66.7% |
| De Witt |
High |
4 |
— |
| DeKalb |
High |
17 |
35.3% |
| Douglas |
High |
4 |
— |
| Edgar |
High |
— |
— |
| Ford |
High |
4 |
— |
| Fulton |
High |
11 |
36.4% |
| Greene |
High |
— |
— |
| Grundy |
High |
9 |
— |
| Hancock |
High |
— |
— |
| Henderson |
High |
— |
— |
| Henry |
High |
11 |
36.4% |
| Iroquois |
High |
6 |
— |
| Jersey |
High |
4 |
— |
| Jo Daviess |
High |
5 |
80% |
| Kane |
High |
77 |
28.6% |
| Kendall |
High |
18 |
27.8% |
| Knox |
High |
10 |
50% |
| LaSalle |
High |
23 |
43.5% |
| Lee |
High |
8 |
— |
| Livingston |
High |
9 |
— |
| Logan |
High |
7 |
— |
| Macon |
High |
23 |
43.5% |
| Marshall |
High |
— |
— |
| Mason |
High |
— |
— |
| McDonough |
High |
4 |
— |
| McLean |
High |
24 |
33.3% |
| Menard |
High |
— |
— |
| Mercer |
High |
5 |
— |
| Morgan |
High |
4 |
100% |
| Moultrie |
High |
— |
— |
| Ogle |
High |
9 |
55.6% |
| Peoria |
High |
31 |
48.4% |
| Piatt |
High |
4 |
— |
| Pike |
High |
5 |
— |
| Putnam |
High |
— |
— |
| Rock Island |
High |
28 |
46.4% |
| Sangamon |
High |
42 |
28.6% |
| Schuyler |
High |
— |
— |
| Scott |
High |
— |
— |
| Stark |
High |
— |
— |
| Stephenson |
High |
7 |
57.1% |
| Tazewell |
High |
24 |
50% |
| Vermilion |
High |
15 |
33.3% |
| Warren |
High |
4 |
— |
| Whiteside |
High |
11 |
36.4% |
| Winnebago |
High |
50 |
40% |
| Woodford |
High |
8 |
50% |
| Bond |
Moderate |
— |
— |
| Christian |
Moderate |
7 |
— |
| Clark |
Moderate |
— |
— |
| Clay |
Moderate |
— |
— |
| Clinton |
Moderate |
5 |
80% |
| Cook |
Moderate |
878 |
28.2% |
| Crawford |
Moderate |
5 |
— |
| Cumberland |
Moderate |
— |
— |
| DuPage |
Moderate |
148 |
30.4% |
| Edwards |
Moderate |
— |
— |
| Effingham |
Moderate |
6 |
— |
| Fayette |
Moderate |
5 |
— |
| Franklin |
Moderate |
8 |
75% |
| Gallatin |
Moderate |
— |
— |
| Hamilton |
Moderate |
— |
— |
| Hardin |
Moderate |
— |
— |
| Jackson |
Moderate |
6 |
66.7% |
| Jasper |
Moderate |
— |
— |
| Jefferson |
Moderate |
10 |
40% |
| Johnson |
Moderate |
— |
— |
| Kankakee |
Moderate |
21 |
33.3% |
| Lake |
Moderate |
119 |
31.1% |
| Lawrence |
Moderate |
— |
— |
| Macoupin |
Moderate |
9 |
44.4% |
| Madison |
Moderate |
51 |
37.3% |
| Marion |
Moderate |
5 |
100% |
| McHenry |
Moderate |
52 |
32.7% |
| Monroe |
Moderate |
5 |
— |
| Montgomery |
Moderate |
5 |
— |
| Perry |
Moderate |
4 |
— |
| Pope |
Moderate |
— |
— |
| Randolph |
Moderate |
5 |
— |
| Richland |
Moderate |
— |
— |
| Saline |
Moderate |
4 |
— |
| Shelby |
Moderate |
4 |
— |
| St. Clair |
Moderate |
43 |
39.5% |
| Union |
Moderate |
— |
— |
| Wabash |
Moderate |
— |
— |
| Washington |
Moderate |
4 |
— |
| Wayne |
Moderate |
— |
— |
| White |
Moderate |
4 |
— |
| Will |
Moderate |
98 |
35.7% |
| Williamson |
Moderate |
13 |
53.8% |
| Alexander |
Low |
— |
— |
| Massac |
Low |
— |
— |
| Pulaski |
Low |
— |
— |
Sources: EPA Map of Radon Zones, CDC Environmental Health Tracking Network
Frequently Asked Questions
How many counties in Illinois have high radon risk?
Illinois has 56 counties classified as EPA Zone 1 (high radon risk), 43 as Zone 2 (moderate), and 3 as Zone 3 (low risk).
Is radon a problem in Illinois?
Illinois has 56 high-risk counties where elevated radon is likely. The EPA recommends all homes in Illinois be tested for radon, regardless of which zone they're in.
How do I check radon levels for my Illinois address?
Enter your ZIP code in the search box above to see your county's EPA radon zone and available testing data. For your specific home's radon level, you'll need a radon test kit.