Radon levels in Winston-Salem, North Carolina
ModerateEPA Zone 2Predicted long-term basement average of 2.3 pCi/L (model estimate) across the 9 modeled ZIP codes in Winston-Salem - about 1.3× the US average of 1.8, about 1.4× the North Carolina average of 1.7. Ranked #1 of 26 North Carolina cities on this site. Most of the city lies in Forsyth County (its ZIPs also reach into 1 other county).
Test Winston-Salem, NC - the EPA says "consider fixing" in this range
The predicted basement average here is 2.3 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.
Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.
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Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.
2.3 ± 0.08
pCi/L predicted basement mean (model SD)
1.4 ± 0.07
pCi/L predicted upstairs (above-ground) mean
1.9-2.8
range of ZIP-level basement predictions in the city
0%
of Winston-Salem ZIPs predicted ≥ 4 pCi/L (78% ≥ 2)
What this means for Winston-Salem
The typical Winston-Salem home is predicted in the 2-4 pCi/L band. The EPA's guidance for this range is to consider fixing, because there is no known safe level and a meaningful minority of homes in a moderate area will test above 4.
The city figure is not a separate estimate: it is the mean of the model's ZIP-code predictions, weighted by the share of the city's land in each ZIP (Census 2020 ZCTA-to-place relationship file). The 1993 EPA zone (2) for Forsyth and the 2001-2021 model agree here.
Comparable North Carolina cities: Asheville (2.2), Hickory (2.2), Mooresville (2.0), Gastonia (2.0).
ZIP codes in Winston-Salem
ZIPs that overlap the city, largest share of its land first. Predicted basement and upstairs means are model estimates; ZIPs the model does not cover show a dash.
| ZIP | Share of city | Basement | Upstairs | Grade |
|---|---|---|---|---|
| 27105 | 19% | 2.1 ± 0.07 | 1.3 | Moderate |
| 27107 | 18% | 2.3 ± 0.07 | 1.1 | Moderate |
| 27106 | 18% | 2.7 ± 0.08 | 1.6 | Moderate |
| 27103 | 12% | 2.4 ± 0.09 | 1.6 | Moderate |
| 27127 | 11% | 1.9 ± 0.08 | 1.4 | Low |
| 27104 | 9% | 2.8 ± 0.05 | 1.6 | Moderate |
| 27101 | 7% | 2.0 ± 0.07 | 1.2 | Moderate |
| 27040 | 3% | 2.0 ± 0.14 | 1.2 | Low |
| 27284 | 3% | 2.2 ± 0.07 | 1.3 | Moderate |
| 27109 | <1% | — | — | no model |
| 27110 | <1% | — | — | no model |
Testing help in North Carolina
We link only state program pages we could verify, and North Carolina's did not respond when we checked, so start from the EPA state radon contacts page. If a test comes back at 4 pCi/L or higher, mitigation typically costs $800-$2,500 installed; use EPA find-a-professional and read the mitigation guide.
Winston-Salem radon questions
- Is radon high in Winston-Salem, North Carolina?
- Moderate. Averaging the model's ZIP-code predictions across Winston-Salem (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 2.3 pCi/L - about 1.3× the US average of 1.8 and about 1.4× the North Carolina average of 1.7. That is in the 2-4 pCi/L range where the EPA says to consider fixing. Winston-Salem ranks 1 of 26 North Carolina cities on this site.
- Which Winston-Salem ZIP codes have the highest radon?
- Predictions for the 9 modeled ZIP codes in Winston-Salem range from 1.9 to 2.8 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 78% at or above 2. The city is fairly uniform, so the city-wide number is a reasonable guide for any neighborhood.
- Should I test for radon in Winston-Salem?
- Yes, soon. With a predicted basement average of 2.3 pCi/L, a meaningful share of Winston-Salem homes will test above the 4 pCi/L action level. Start with a short-term kit; if it reads 2 or higher, confirm with a long-term test or a continuous monitor before paying for mitigation.
- What does EPA Radon Zone 2 mean for Winston-Salem?
- Winston-Salem sits mainly in Forsyth County, which the EPA classifies as Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and covers whole counties. The 2001-2021 model agrees with the zone for the city. Neither replaces a test of your own home.
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