Radon in West Virginia: radon map by county
EPA's Map of Radon Zones puts 20 of West Virginia's 55 counties in Zone 1 (predicted average indoor radon above 4 pCi/L), 29 in Zone 2 and 6 in Zone 3. Of 7,386 building tests that radon laboratories reported for 2008 to 2017, 38% were at or above EPA's 4 pCi/L action level, against 36.5% nationally (number 18 of 42 states with 1,000+ tests). The highest county share is Morgan County (58.1% of 190 tests).
Radon by county in West Virginia
| County | EPA zone | Lab tests | Median | 4+ pCi/L |
|---|---|---|---|---|
| Barbour County | Zone 2 | 11 | 2.0 | 25% |
| Berkeley County | Zone 1 | 2,010 | 4.0 | 50.7% |
| Boone County | Zone 3 | 7 | 0.1 | 14.3% |
| Braxton County | Zone 2 | 9 | 1.3 | 25% |
| Brooke County | Zone 1 | 119 | 3.4 | 43.9% |
| Cabell County | Zone 2 | 122 | 2.0 | 16.6% |
| Calhoun County | Zone 2 | 3 | 2.4 | 0% |
| Clay County | Zone 2 | 1 | 0.1 | 0% |
| Doddridge County | Zone 2 | 1 | 0.5 | 0% |
| Fayette County | Zone 2 | 17 | 0.8 | 0% |
| Gilmer County | Zone 2 | 7 | 2.1 | 12.5% |
| Grant County | Zone 1 | 94 | 1.1 | 9.8% |
| Greenbrier County | Zone 1 | 119 | 4.5 | 52.3% |
| Hampshire County | Zone 1 | 69 | 2.8 | 38.9% |
| Hancock County | Zone 1 | 264 | 3.9 | 49.1% |
| Hardy County | Zone 1 | 35 | 1.6 | 22.6% |
| Harrison County | Zone 2 | 143 | 2.6 | 36.4% |
| Jackson County | Zone 2 | 19 | 2.5 | 25% |
| Jefferson County | Zone 1 | 736 | 4.4 | 53.2% |
| Kanawha County | Zone 3 | 200 | 2.2 | 20.6% |
| Lewis County | Zone 2 | 21 | 2.0 | 13% |
| Lincoln County | Zone 2 | 8 | 1.9 | 18.2% |
| Logan County | Zone 3 | 8 | 1.4 | 0% |
| Marion County | Zone 2 | 206 | 2.6 | 29.1% |
| Marshall County | Zone 1 | 194 | 2.5 | 31.9% |
| Mason County | Zone 2 | 11 | 2.4 | 23.1% |
| McDowell County | Zone 3 | 3 | 2.5 | 0% |
| Mercer County | Zone 1 | 70 | 2.1 | 33.7% |
| Mineral County | Zone 1 | 53 | 2.8 | 42.1% |
| Mingo County | Zone 3 | 5 | 1.0 | 0% |
| Monongalia County | Zone 1 | 817 | 1.9 | 19% |
| Monroe County | Zone 1 | 9 | 3.6 | 33.3% |
| Morgan County | Zone 1 | 190 | 5.8 | 58.1% |
| Nicholas County | Zone 2 | 10 | 2.6 | 30.8% |
| Ohio County | Zone 1 | 770 | 3.2 | 40.3% |
| Pendleton County | Zone 1 | 20 | 2.5 | 30.9% |
| Pleasants County | Zone 2 | 15 | 4.0 | 50% |
| Pocahontas County | Zone 1 | 10 | 1.0 | 12.5% |
| Preston County | Zone 1 | 158 | 2.5 | 36.9% |
| Putnam County | Zone 2 | 35 | 1.5 | 23.1% |
| Raleigh County | Zone 2 | 36 | 1.4 | 16.7% |
| Randolph County | Zone 2 | 26 | 2.5 | 36.4% |
| Ritchie County | Zone 2 | 10 | 1.9 | 5.6% |
| Roane County | Zone 2 | 16 | 2.3 | 36.4% |
| Summers County | Zone 1 | 8 | 1.5 | 13.3% |
| Taylor County | Zone 2 | 26 | 2.2 | 28.1% |
| Tucker County | Zone 2 | 8 | 1.8 | 27.8% |
| Tyler County | Zone 2 | 24 | 1.8 | 22.9% |
| Upshur County | Zone 2 | 23 | 2.6 | 20.7% |
| Wayne County | Zone 2 | 17 | 1.7 | 15.8% |
| Webster County | Zone 2 | 7 | 1.3 | 21.4% |
| Wetzel County | Zone 1 | 28 | 2.7 | 35.2% |
| Wirt County | Zone 2 | 6 | 1.6 | 0% |
| Wood County | Zone 2 | 549 | 1.8 | 15.9% |
| Wyoming County | Zone 3 | 3 | 0.8 | 33.3% |
Lab tests: buildings tested by radon laboratories, 2008 to 2017; median in pCi/L; “4+ pCi/L” is the share of tests at or above EPA's action level. n/a: no value on file (no tests, or too few to report).
What the zones mean
Zone 1 counties have a predicted average indoor radon screening level above 4 pCi/L, Zone 2 from 2 to 4 pCi/L and Zone 3 below 2 pCi/L. The prediction is from 1993 indoor measurements, geology, aerial radioactivity, soils and foundation types. EPA: “This map should not be used to determine if individual homes need to be tested.” EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of exposure.
Radon in West Virginia: questions
What radon zone is West Virginia?
EPA's 1993 map does not give states one zone; it zones each county. In West Virginia, 20 counties are Zone 1, 29 Zone 2 and 6 Zone 3. EPA says the map "should not be used to determine if individual homes need to be tested".
Which West Virginia counties have the highest radon levels?
By the share of laboratory tests at or above 4 pCi/L for 2008 to 2017 (counties with 20 or more tests): Morgan County 58.1% (median 5.8 pCi/L, 190 tests); Jefferson County 53.2% (median 4.4 pCi/L, 736 tests); Greenbrier County 52.3% (median 4.5 pCi/L, 119 tests); Berkeley County 50.7% (median 4.0 pCi/L, 2,010 tests); Hancock County 49.1% (median 3.9 pCi/L, 264 tests).
How common is high radon in West Virginia?
38% of the 7,386 tests in the laboratory data for West Virginia (2008 to 2017) were at or above 4 pCi/L; the national share was 36.5%. Buildings are tested by choice, often because of a sale or a concern, so the share describes the tests on file, not every home.
Should I test for radon in West Virginia?
Yes. EPA recommends testing every home no matter where it is, fixing it at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, because there is no known safe level of radon exposure.
States bordering West Virginia
Other free hazard lookups
- Radon by county and ZIP codeEPA radon zone and the radon test results on file for any county, ZIP code or address.
- Fault lines near an addressUSGS-mapped earthquake faults within 5 miles, their age and slip rate, and the USGS seismic hazard value.
- Power lines near an addressHigh-voltage transmission lines within 1 mile from federal maps, with voltage and distance.
- Flood zone lookupThe FEMA flood zone mapped at any US address. Not an official flood zone determination.
- Superfund sites near an addressThe nearest EPA Superfund (NPL) sites and their status.
All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).
Superfund sites in West Virginia · Radon map of every state
Data compiled 2026-10-20. County-level screening information, not a radon measurement of any building.