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Radon Levels in Forsyth County, North Carolina

EPA puts Forsyth County in Zone 2, its middle radon zone, and only 17 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    28.9%

    6.3 pts above NC

    Forsyth
    28.9%
    NC
    22.6%

    6,273 tests, 2008 to 2017

  • Median result

    2.3pCi/L

    Below action level

    Forsyth
    2.3 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    6,273

    4th of 75 by tests

    Forsyth
    6,273
    Wake
    9,694

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in NC

    24 of 75

    Middle half

    Forsyth
    28.9%
    Transylvania
    47.8%

    By share, of 75 with 30+ tests

Read a result for Forsyth County

Starts at Forsyth County's median, 2.3 pCi/L

2.3pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 2.3 pCi/L

Between 2 and 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 4 and aboveEPA says fix it

This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Forsyth County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Forsyth County, At a glance

Forsyth County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Forsyth County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 76% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Forsyth County, 2022

Share of reported tests at or above 4 pCi/L, by year, Forsyth County
Share of reported tests at or above 4 pCi/L, by year, Forsyth County
YearShare of reported tests at or above 4 pCi/L
201429.3%
202026.1%
202118.1%
202223.5%

2022: 23.5%. Across these years the share ran from 18.1% to 29.3%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 17 tests were reported to CDC for Forsyth County over 2022, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.

Measured: CDC tracking data. Figure above: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).

How to read these figures

Forsyth County, Compared

Forsyth County radon figures, compared

Calculated by Radon411

Forsyth County's 6,273 reported tests over the 2008 to 2017 laboratory totals had a middle value of 2.3 pCi/L and a maximum of 62.6 pCi/L, and 28.9% reached 4 pCi/L. North Carolina as a whole (99 North Carolina counties, pooled) comes to 22.6%: 6.3 points lower than here.

The newest figure, in 2022, counts only 17 tests (23.5% at or above 4 pCi/L), too few to compare, so this reading uses the 6,273-test figure.

Among its state's counties it ranks 24th of 75 North Carolina counties with 30 or more tests for the same period. Statewide for the same period, Transylvania County reported the highest share (47.8%) and Nash County the lowest (0.0%).

Below the action level, 2,701 tests (43.1%) came in under 2 pCi/L, against 55.6% statewide, and 1,760 tests (28.1%) fell between 2 and 4, against 21.8% statewide. The busiest year on file was 2014, with 685 tests reported; the quietest, 2022, had 17.

EPA's 1993 zone map puts Forsyth County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 76% of the county's land moderate radon potential.

Next door, the shares run from 7.9% in Guilford County to 33.3% in Surry County, with Yadkin County, Rockingham County and Davidson County below Forsyth County. Over 3 years of annual figures the share fell 11.2 points, from 29.3% in 2014 to 18.1% in 2021; its peak was 29.3% in 2014.

CDC also counts 239 tests taken after mitigation in Forsyth County for the same period: tests in homes where a fix was already in.

Share of reported tests at or above 4 pCi/L by year, Forsyth County against North Carolina2014 to 2021, years with 30 or more tests: Forsyth County 29.3% to 18.1%, the state's pooled share 14.9% in 2021.
Forsyth CountyNorth Carolina, pooled
Share of reported tests at or above 4 pCi/L by year, Forsyth County against North Carolina: data table
YearTestsForsyth County, at or above 4 pCi/LNorth Carolina, pooled
201468529.3%21.9%
202054126.1%21.1%
202134318.1%14.9%
Forsyth County against North Carolina, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Forsyth County
Forsyth County6,27328.9%2.3 pCi/LThis county
North Carolina, pooled99 counties, pooled73,13922.6%Not pooled−6.3 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+6.8 points
Transylvania Countyhighest in the state3,86247.8%3.7 pCi/L+18.9 points
Nash Countylowest in the state300.0%0.2 pCi/L−28.9 points
Surry County, NCborders it85533.3%2.4 pCi/L+4.4 points
Yadkin County, NCborders it19928.6%2.2 pCi/L−0.3 points
Rockingham County, NCborders it83527.3%2.1 pCi/L−1.6 points
Davidson County, NCborders it1,26525.5%1.8 pCi/L−3.4 points
Stokes County, NCborders it59221.6%1.8 pCi/L−7.3 points
Davie County, NCborders it69417.4%1.7 pCi/L−11.5 points
Guilford County, NCborders it6,8707.9%0.9 pCi/L−21.0 points
Where Forsyth County's reported results fell, 2008 to 2017, laboratory, beside North Carolina and the United States
ResultForsyth County testsForsyth County shareNorth Carolina shareU.S. shareAgainst North Carolina
Under 2 pCi/L2,70143.1%55.6%39.6%−12.5 points
2 to 4 pCi/L1,76028.1%21.8%24.7%+6.3 points
4 pCi/L and above1,81228.9%22.6%35.7%+6.3 points
Forsyth County ranked among the 75 North Carolina counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Yancey County19 of 7529031.0%1.9 pCi/L
Haywood County20 of 751,87230.6%2.2 pCi/L
Polk County21 of 7559429.8%2.4 pCi/L
Buncombe County22 of 756,35929.0%2.3 pCi/L
Lincoln County23 of 7570829.0%2.4 pCi/L
Forsyth County24 of 756,27328.9%2.3 pCi/L
Yadkin County25 of 7519928.6%2.2 pCi/L
Mitchell County26 of 7543328.6%2.1 pCi/L
Burke County27 of 7594028.3%2.4 pCi/L
Jackson County28 of 751,02627.7%2.2 pCi/L
Caldwell County29 of 7586127.6%2.5 pCi/L
Forsyth County radon tests by year, against North Carolina's pooled share
YearTestsAt or above 4 pCi/LMedianHighestNorth Carolina, pooledChange from the row before
20221723.5%2.0 pCi/L7.0 pCi/L10.7%+5.4 points
202134318.1%1.0 pCi/L19.0 pCi/L14.9%−8.0 points
202054126.1%2.0 pCi/L60.8 pCi/L21.1%−3.2 points
201468529.3%2.0 pCi/L33.1 pCi/L21.9%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Forsyth County, Geology

The ground under Forsyth County

Predicted

Most of the ground under Forsyth County is one class on USGS's geologic map: 76.3% of its land is moderate radon potential, with 23.7% low. The map puts 55.0% of Forsyth County in the area it calls Milton Belt and 23.7% in Charlotte Belt, with one smaller area beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 8, in the low band (5 to 8).

USGS's geologic areas under Forsyth County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Milton BeltProterozoic-Cambrian biotite gneiss and felsic mica gneiss.Moderate1155.0%
Charlotte BeltIgneous rocks, including granite, gabbro, and diorite.Low823.7%
Inner Piedmont BeltProterozoic through Cambrian biotite gneiss and schist, and mica schist.Moderate1121.3%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Forsyth County beside the ground around it

Across North Carolina 1.3% of the land is rated high; none of Forsyth County's is. Of the 7 counties that border it, 1 has more high-potential ground, Stokes County the most at 0.1%.

Share of land by USGS radon potential: Forsyth County, the 7 counties bordering it and North Carolina
AreaEPA zoneLow potentialModerate potentialHigh potential
Forsyth CountyZone 223.7%76.3%None
Stokes CountyZone 210.3%89.7%0.1%
Davie CountyZone 392.3%7.7%None
Yadkin CountyZone 23.2%96.8%None
Davidson CountyZone 3100%NoneNone
Guilford CountyZone 390.9%9.1%None
Surry CountyZone 2None100%None
Rockingham CountyZone 119.2%80.7%None
North Carolina100 counties, pooled by land areaVaries64.8%33.0%1.3%

The map rates the ground, not the air in any home.

Local help

Forsyth County, Local resources

Radon testing and mitigation in Forsyth County

What North Carolina's program says
Licensing of radon professionals
The North Carolina Radon Program is presently developing a Radon Proficiency Program as directed by Session Law 2023-91 House Bill 782 .

What it means

Forsyth County, Questions

Questions about radon in Forsyth County

Are radon levels high in Forsyth County?

In 2022, 23.5% of the radon tests reported to CDC for Forsyth County, North Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.0 pCi/L. Of 75 North Carolina counties with 30 or more tests for the same period, 23 reported a higher share; pooled, the state comes to 22.6%.

Which counties border Forsyth County?

Forsyth County borders 7 counties: Stokes County, Davie County, Yadkin County, Davidson County, Guilford County, Surry County and Rockingham County.

Products

Forsyth County, Products

Testing a home in Forsyth County

In Forsyth County, 28.9% of 6,273 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.6% pooled across North Carolina. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Forsyth County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Forsyth County homes, compared

Explore

Forsyth County, Bordering counties

Counties bordering Forsyth County

Calculated by Radon411

Forsyth County, Cities and towns

Cities and towns in Forsyth County

The Census Bureau estimates 401,718 residents in Forsyth County for July 1, 2025, 19,100 more than in 2020 (+5.0%). That works out to 985 people per square mile of land. Winston-Salem alone is home to 257,271 of them, 64.0% of the total. Testing is reported here more often than across the state: CDC's 6,273 reported tests for 2008 to 2017 come to 15.6 for every 1,000 residents (2025 estimate), against 6.5 for North Carolina.

From Winston-Salem to Bethania, CDC publishes no figure by town: each reads Forsyth County's.

The cities and towns in Forsyth County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Winston-Salem257,271+3.2%64.0%
High Pointextends beyond Forsyth County120,571+5.1%Counted whole
Kernersvilleextends beyond Forsyth County29,128+9.6%Counted whole
Clemmons22,808+7.4%5.7%
Lewisville14,421+7.5%3.6%
Kingextends beyond Forsyth County7,977+10.6%Counted whole
Walkertown6,120+7.4%1.5%
Rural Hall3,607+7.2%0.9%
Tobaccovilleextends beyond Forsyth County2,770+7.7%Counted whole
Bethania367+7.3%Under 0.1%

10 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025). A place that extends beyond Forsyth County is counted whole, so it has no share.

Forsyth County, Homes

Homes in Forsyth County

Of Forsyth County's 173,220 homes, 66% are detached houses, against 65% across North Carolina; 21% are in buildings of five or more homes. Half of its homes were built before 1983, close to North Carolina's 1990: 20% date from before 1960 and 26% from 2000 or later. 63% of occupied homes are lived in by their owner (North Carolina: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Forsyth County, North Carolina, 2019 to 2023
HomesForsyth CountyNorth Carolina
Housing units173,2204,815,195
Detached houses66%65%
In buildings of 5 or more21%14%
Mobile homes3%11%
Built before 196020%14%
Built since 200026%33%
Middle year built19831990
Owner-occupied63%66%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.