Radon in North Carolina: radon map by county

EPA's Map of Radon Zones puts 8 of North Carolina's 100 counties in Zone 1 (predicted average indoor radon above 4 pCi/L), 31 in Zone 2 and 61 in Zone 3. Of 43,945 building tests that radon laboratories reported for 2008 to 2017, 22.5% were at or above EPA's 4 pCi/L action level, against 36.5% nationally (number 33 of 42 states with 1,000+ tests). The highest county share is Transylvania County (47.8% of 1,668 tests).

counties in Zone 1 (above 4 pCi/L predicted)

counties in Zone 2 (2 to 4)

counties in Zone 3 (below 2)

22.5%

of 43,945 lab tests at or above 4 pCi/L

Radon by county in North Carolina

EPA radon zone and radon test results for each county in North Carolina
County	EPA zone	Lab tests	Median	4+ pCi/L
Alamance County	Zone 3	320	0.5	3.7%
Alexander County	Zone 2	201	2.5	32.8%
Alleghany County	Zone 1	198	3.3	41.1%
Anson County	Zone 3	20	0.6	0%
Ashe County	Zone 2	520	2.5	34.1%
Avery County	Zone 2	105	2.8	38.8%
Beaufort County	Zone 3	20	0.1	0%
Bertie County	Zone 3	3	1.1	25%
Bladen County	Zone 3	12	0.1	0%
Brunswick County	Zone 3	47	0.5	0%
Buncombe County	Zone 1	3,901	2.3	29%
Burke County	Zone 2	585	2.4	28.3%
Cabarrus County	Zone 3	519	1.0	8.8%
Caldwell County	Zone 2	488	2.5	27.6%
Camden County	Zone 3	n/a	n/a	n/a
Carteret County	Zone 3	38	0.1	0%
Caswell County	Zone 2	38	1.6	14.9%
Catawba County	Zone 2	765	2.0	24.8%
Chatham County	Zone 3	346	1.1	10.9%
Cherokee County	Zone 1	645	3.4	43.2%
Chowan County	Zone 3	4	0.1	0%
Clay County	Zone 2	213	3.0	43%
Cleveland County	Zone 2	365	2.8	39.5%
Columbus County	Zone 3	26	0.1	0%
Craven County	Zone 3	86	0.2	0%
Cumberland County	Zone 3	134	0.7	1.9%
Currituck County	Zone 3	6	0.3	0%
Dare County	Zone 3	31	0.1	26.8%
Davidson County	Zone 3	844	1.8	25.5%
Davie County	Zone 3	450	1.7	17.4%
Duplin County	Zone 3	5	0.1	0%
Durham County	Zone 3	943	0.7	4.3%
Edgecombe County	Zone 3	8	0.1	0%
Forsyth County	Zone 2	4,636	2.3	28.9%
Franklin County	Zone 2	126	1.4	19.1%
Gaston County	Zone 2	431	1.5	19.1%
Gates County	Zone 3	1	0.1	0%
Graham County	Zone 2	50	3.0	42%
Granville County	Zone 3	99	0.8	10.5%
Greene County	Zone 3	7	0.1	0%
Guilford County	Zone 3	3,466	0.9	7.9%
Halifax County	Zone 3	48	2.6	42.4%
Harnett County	Zone 3	110	0.6	0.6%
Haywood County	Zone 2	1,015	2.2	30.6%
Henderson County	Zone 1	2,129	3.3	41.8%
Hertford County	Zone 3	2	0.4	0%
Hoke County	Zone 3	18	0.8	0%
Hyde County	Zone 3	4	0.1	0%
Iredell County	Zone 2	692	1.8	21.8%
Jackson County	Zone 2	518	2.2	27.7%
Johnston County	Zone 3	369	0.7	8.2%
Jones County	Zone 3	1	1.8	0%
Lee County	Zone 3	79	0.9	1.1%
Lenoir County	Zone 3	13	0.1	0%
Lincoln County	Zone 2	453	2.4	29%
Macon County	Zone 2	694	1.4	17.1%
Madison County	Zone 2	161	1.3	16.7%
Martin County	Zone 3	4	0.6	0%
McDowell County	Zone 2	537	2.7	37.5%
Mecklenburg County	Zone 3	2,620	0.9	8.5%
Mitchell County	Zone 1	282	2.1	28.6%
Montgomery County	Zone 3	62	1.5	20.4%
Moore County	Zone 3	79	1.3	19.2%
Nash County	Zone 3	23	0.2	0%
New Hanover County	Zone 3	89	0.1	3.4%
Northampton County	Zone 3	38	3.4	40.3%
Onslow County	Zone 3	156	0.5	2.7%
Orange County	Zone 3	647	1.1	10.7%
Pamlico County	Zone 3	1	0.1	0%
Pasquotank County	Zone 3	5	0.6	37.5%
Pender County	Zone 3	15	0.1	11.8%
Perquimans County	Zone 3	4	0.8	0%
Person County	Zone 3	140	1.3	17.4%
Pitt County	Zone 3	83	0.1	1%
Polk County	Zone 2	340	2.4	29.8%
Randolph County	Zone 3	281	0.9	7.1%
Richmond County	Zone 3	47	0.6	0%
Robeson County	Zone 3	47	0.8	3.8%
Rockingham County	Zone 1	532	2.1	27.3%
Rowan County	Zone 3	387	1.4	17.7%
Rutherford County	Zone 2	317	2.4	25.6%
Sampson County	Zone 3	11	0.6	0%
Scotland County	Zone 3	30	1.0	3.2%
Stanly County	Zone 3	156	2.2	25.3%
Stokes County	Zone 2	357	1.8	21.6%
Surry County	Zone 2	473	2.4	33.3%
Swain County	Zone 2	83	3.4	44%
Transylvania County	Zone 1	1,668	3.7	47.8%
Tyrrell County	Zone 3	1	0.1	0%
Union County	Zone 3	651	1.1	11.2%
Vance County	Zone 2	71	1.5	14.7%
Wake County	Zone 2	5,174	1.0	9.6%
Warren County	Zone 2	52	3.0	42.7%
Washington County	Zone 3	1	0.1	0%
Watauga County	Zone 1	803	3.5	45.1%
Wayne County	Zone 3	42	0.6	8.2%
Wilkes County	Zone 2	269	3.5	44.3%
Wilson County	Zone 3	17	0.4	0%
Yadkin County	Zone 2	147	2.2	28.6%
Yancey County	Zone 2	195	1.9	31%

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.

Buying in North Carolina? Order a North Carolina title search: owner of record, deeds, mortgages and liens in Durham County, Forsyth County, $49 per report.

Radon in North Carolina: questions

What radon zone is North Carolina?

EPA's 1993 map does not give states one zone; it zones each county. In North Carolina, 8 counties are Zone 1, 31 Zone 2 and 61 Zone 3. EPA says the map "should not be used to determine if individual homes need to be tested".

Which North Carolina 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): Transylvania County 47.8% (median 3.7 pCi/L, 1,668 tests); Watauga County 45.1% (median 3.5 pCi/L, 803 tests); Wilkes County 44.3% (median 3.5 pCi/L, 269 tests); Swain County 44% (median 3.4 pCi/L, 83 tests); Cherokee County 43.2% (median 3.4 pCi/L, 645 tests).

How common is high radon in North Carolina?

22.5% of the 43,945 tests in the laboratory data for North Carolina (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.

Does North Carolina publish its own radon test data?

North Carolina's radon program reports county test results; the latest year with county results is 2022, shown on each county page.

Should I test for radon in North Carolina?

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 North Carolina

Radon in Georgia (4 of 159 in Zone 1)Radon in South Carolina (1 of 46 in Zone 1)Radon in Tennessee (39 of 95 in Zone 1)Radon in Virginia (62 of 133 in Zone 1)

Other free hazard lookups

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 North Carolina · Radon map of every state

Data compiled 2026-10-20. County-level screening information, not a radon measurement of any building.