Radon by ZIP

Radon zones in Wisconsin

Last updated

EPA’s Map of Radon Zones places 72 Wisconsin counties in its three radon potential zones: 28 in Zone 1 (highest), 44 in Zone 2 (moderate), and 0 in Zone 3 (low).

28Zone 1 · Highest potential
44Zone 2 · Moderate potential
0Zone 3 · Low potential

What this means for Wisconsin homes

Most Wisconsin counties fall in Zone 2. EPA predicts moderate average indoor levels (2 to 4 pCi/L) across much of Wisconsin. Many homes will be below the action level, but many will not, and only a test can tell which.

EPA’s guidance is the same everywhere: test your home, fix it if the level is 4 pCi/L or higher, and consider fixing between 2 and 4 pCi/L. The zone map is from 1993 and should not be used to decide whether a single home needs testing.

Wisconsin radon program

EPA lists the following state contact for Wisconsin: WI Radon Program, phone 608-267-7199. Website: www.dhs.wisconsin.gov/radon/infocenters.htm. State programs can tell you about local testing data, free or discounted test kits, disclosure rules for home sales, and credentialed radon professionals.

Wisconsin counties and their EPA radon zones

CountyEPA radon zone
Adams CountyZone 2
Ashland CountyZone 2
Barron CountyZone 2
Bayfield CountyZone 2
Brown CountyZone 2
Buffalo CountyZone 1
Burnett CountyZone 2
Calumet CountyZone 2
Chippewa CountyZone 2
Clark CountyZone 2
Columbia CountyZone 2
Crawford CountyZone 1
Dane CountyZone 1
Dodge CountyZone 1
Door CountyZone 1
Douglas CountyZone 2
Dunn CountyZone 2
Eau Claire CountyZone 2
Florence CountyZone 2
Fond du Lac CountyZone 1
Forest CountyZone 2
Grant CountyZone 1
Green CountyZone 1
Green Lake CountyZone 1
Iowa CountyZone 1
Iron CountyZone 2
Jackson CountyZone 2
Jefferson CountyZone 1
Juneau CountyZone 2
Kenosha CountyZone 2
Kewaunee CountyZone 2
La Crosse CountyZone 2
Lafayette CountyZone 1
Langlade CountyZone 1
Lincoln CountyZone 2
Manitowoc CountyZone 2
Marathon CountyZone 1
Marinette CountyZone 2
Marquette CountyZone 2
Menominee CountyZone 1
Milwaukee CountyZone 2
Monroe CountyZone 2
Oconto CountyZone 2
Oneida CountyZone 2
Outagamie CountyZone 2
Ozaukee CountyZone 2
Pepin CountyZone 1
Pierce CountyZone 1
Polk CountyZone 2
Portage CountyZone 1
Price CountyZone 2
Racine CountyZone 2
Richland CountyZone 1
Rock CountyZone 1
Rusk CountyZone 2
Sauk CountyZone 2
Sawyer CountyZone 2
Shawano CountyZone 1
Sheboygan CountyZone 2
St. Croix CountyZone 1
Taylor CountyZone 2
Trempealeau CountyZone 2
Vernon CountyZone 1
Vilas CountyZone 2
Walworth CountyZone 1
Washburn CountyZone 2
Washington CountyZone 1
Waukesha CountyZone 1
Waupaca CountyZone 1
Waushara CountyZone 2
Winnebago CountyZone 2
Wood CountyZone 1

County names follow the 2020 Census. Zones from the EPA Map of Radon Zones (text version). Rows marked “zone of” use the zone EPA gave the predecessor or surrounding county.

Next steps: read how to test your home, check a result with the level calculator, or look up a single address by ZIP code.

Sources

  1. U.S. EPA, EPA Map of Radon Zones (text version)
  2. U.S. EPA, EPA Map of Radon Zones and Supplemental Information (state radon contacts)
  3. U.S. EPA, EPA Maps of Radon Zones and Supporting Documents by State