Radon levels in South Dakota: Moderate
The model predicts a population-weighted basement average of 3.9 pCi/L across South Dakota's 66 counties - about 2.1× the US average of 1.8 pCi/L. Above-ground floors average 2.2 pCi/L.
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.
48 / 66
EPA Zone 1 counties (73%)
18 / 0
Zone 2 / Zone 3 counties
34
counties predicted ≥ 4 pCi/L
42.1%
of ZIP codes predicted ≥ 4 pCi/L
South Dakota counties by predicted radon
Sorted highest to lowest predicted basement average. 66 counties.
| County | Predicted basement | Upstairs | Grade | EPA zone | ZIPs |
|---|---|---|---|---|---|
| Jerauld County | 5.2 pCi/L | 2.5 | High | EPA Zone 1 | 1 |
| Yankton County | 4.9 pCi/L | 2.5 | High | EPA Zone 1 | 7 |
| Hughes County | 4.8 pCi/L | 2.3 | High | EPA Zone 1 | 3 |
| Bon Homme County | 4.8 pCi/L | 2.5 | High | EPA Zone 1 | 5 |
| Hutchinson County | 4.7 pCi/L | 2.4 | High | EPA Zone 1 | 6 |
| Codington County | 4.6 pCi/L | 2.6 | High | EPA Zone 1 | 6 |
| Pennington County | 4.6 pCi/L | 2.6 | High | EPA Zone 2 | 9 |
| Hyde County | 4.5 pCi/L | 2.5 | High | EPA Zone 1 | 2 |
| Aurora County | 4.5 pCi/L | 2.4 | High | EPA Zone 1 | 3 |
| Douglas County | 4.5 pCi/L | 2.4 | High | EPA Zone 1 | 5 |
| Turner County | 4.5 pCi/L | 2.4 | High | EPA Zone 1 | 7 |
| Kingsbury County | 4.5 pCi/L | 2.5 | High | EPA Zone 1 | 6 |
| Hanson County | 4.4 pCi/L | 2.4 | High | EPA Zone 1 | 3 |
| Miner County | 4.4 pCi/L | 2.5 | High | EPA Zone 1 | 4 |
| Charles Mix County | 4.4 pCi/L | 2.3 | High | EPA Zone 1 | 5 |
| Brule County | 4.4 pCi/L | 2.3 | High | EPA Zone 1 | 3 |
| Lawrence County | 4.4 pCi/L | 2.2 | High | EPA Zone 2 | 6 |
| Sanborn County | 4.4 pCi/L | 2.5 | High | EPA Zone 1 | 3 |
| Hand County | 4.3 pCi/L | 2.5 | High | EPA Zone 1 | 6 |
| Deuel County | 4.3 pCi/L | 2.5 | High | EPA Zone 1 | 7 |
| Moody County | 4.3 pCi/L | 2.4 | High | EPA Zone 1 | 4 |
| Sully County | 4.3 pCi/L | 2.4 | High | EPA Zone 1 | 2 |
| Hamlin County | 4.3 pCi/L | 2.5 | High | EPA Zone 1 | 5 |
| Lake County | 4.3 pCi/L | 2.4 | High | EPA Zone 1 | 7 |
| Potter County | 4.3 pCi/L | 2.4 | High | EPA Zone 1 | 4 |
| McCook County | 4.2 pCi/L | 2.4 | High | EPA Zone 1 | 6 |
| Faulk County | 4.2 pCi/L | 2.3 | High | EPA Zone 1 | 4 |
| Custer County | 4.2 pCi/L | 2.1 | High | EPA Zone 2 | 3 |
| Spink County | 4.2 pCi/L | 2.4 | High | EPA Zone 1 | 10 |
| Brown County | 4.2 pCi/L | 2.4 | High | EPA Zone 1 | 12 |
| Clark County | 4.1 pCi/L | 2.4 | High | EPA Zone 1 | 6 |
| Grant County | 4.1 pCi/L | 2.4 | High | EPA Zone 1 | 10 |
| Beadle County | 4.1 pCi/L | 2.3 | High | EPA Zone 1 | 8 |
| Brookings County | 4.0 pCi/L | 2.3 | High | EPA Zone 1 | 6 |
| Walworth County | 4.0 pCi/L | 2.4 | Moderate | EPA Zone 1 | 3 |
| Marshall County | 4.0 pCi/L | 2.3 | Moderate | EPA Zone 1 | 6 |
| McPherson County | 3.9 pCi/L | 2.3 | Moderate | EPA Zone 1 | 4 |
| Day County | 3.9 pCi/L | 2.3 | Moderate | EPA Zone 1 | 7 |
| Roberts County | 3.9 pCi/L | 2.2 | Moderate | EPA Zone 1 | 8 |
| Union County | 3.9 pCi/L | 2.3 | Moderate | EPA Zone 1 | 4 |
| Davison County | 3.8 pCi/L | 2.4 | Moderate | EPA Zone 1 | 3 |
| Buffalo County | 3.8 pCi/L | 2.1 | Moderate | EPA Zone 1 | 2 |
| Stanley County | 3.7 pCi/L | 2.2 | Moderate | EPA Zone 1 | 2 |
| Butte County | 3.7 pCi/L | 2.2 | Moderate | EPA Zone 2 | 4 |
| Clay County | 3.7 pCi/L | 2.0 | Moderate | EPA Zone 1 | 3 |
| Meade County | 3.7 pCi/L | 1.9 | Moderate | EPA Zone 2 | 12 |
| Campbell County | 3.6 pCi/L | 2.2 | Moderate | EPA Zone 1 | 2 |
| Lincoln County | 3.5 pCi/L | 2.1 | Moderate | EPA Zone 1 | 9 |
| Lyman County | 3.4 pCi/L | 1.9 | Moderate | EPA Zone 1 | 6 |
| Fall River County | 3.3 pCi/L | 1.8 | Moderate | EPA Zone 2 | 5 |
| Perkins County | 3.3 pCi/L | 2.0 | Moderate | EPA Zone 1 | 6 |
| Minnehaha County | 3.2 pCi/L | 2.0 | Moderate | EPA Zone 1 | 16 |
| Dewey County | 3.2 pCi/L | 2.0 | Moderate | EPA Zone 2 | 4 |
| Corson County | 3.1 pCi/L | 2.0 | Moderate | EPA Zone 1 | 8 |
| Harding County | 3.1 pCi/L | 1.8 | Moderate | EPA Zone 2 | 5 |
| Tripp County | 3.1 pCi/L | 1.8 | Moderate | EPA Zone 2 | 6 |
| Edmunds County | 3.1 pCi/L | 2.2 | Moderate | EPA Zone 1 | 3 |
| Jones County | 3.1 pCi/L | 1.6 | Moderate | EPA Zone 2 | 3 |
| Gregory County | 3.0 pCi/L | 1.6 | Moderate | EPA Zone 2 | 6 |
| Haakon County | 3.0 pCi/L | 1.7 | Moderate | EPA Zone 2 | 3 |
| Mellette County | 2.9 pCi/L | 1.6 | Moderate | EPA Zone 2 | 4 |
| Ziebach County | 2.8 pCi/L | 1.7 | Moderate | EPA Zone 2 | 2 |
| Jackson County | 2.8 pCi/L | 1.6 | Moderate | EPA Zone 2 | 4 |
| Bennett County | 2.7 pCi/L | 1.7 | Moderate | EPA Zone 2 | 3 |
| Oglala Lakota County | 2.6 pCi/L | 1.5 | Moderate | EPA Zone 2 | 7 |
| Todd County | 2.6 pCi/L | 1.4 | Moderate | EPA Zone 2 | 3 |
South Dakota radon questions
- Is radon high in South Dakota?
- South Dakota's population-weighted predicted basement average is 3.9 pCi/L, about 2.1× the US average of 1.8. 34 of its 66 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 32 are in the 2-4 "consider fixing" range and 0 are below 2. 42.1% of South Dakota ZIP codes are predicted at 4 or higher.
- Which South Dakota county has the highest radon?
- Jerauld County has the highest predicted basement average in South Dakota at 5.2 pCi/L (EPA Zone 1). The lowest is Todd County at 2.6 pCi/L. These are modeled area averages; individual homes in any county can test far higher.
- How many EPA Zone 1 counties are in South Dakota?
- 48 of South Dakota's 66 counties (73%) are EPA Zone 1 (highest potential), 18 are Zone 2 and 0 are Zone 3. The EPA zone map dates from 1993; the predicted values on this page come from a 2001-2021 model built on millions of actual tests, so the two can disagree for a given county.
- Should I test for radon in South Dakota?
- Yes - with some urgency. South Dakota's predicted average is in the moderate range, and 100% of its ZIP codes are predicted at 2 pCi/L or higher. A short-term charcoal kit or a continuous digital monitor will tell you your actual level within days.
South Dakota radon program
Many states offer free or discounted test kits and keep lists of certified mitigators. Find the South Dakota radon office through the EPA state radon contacts page. Then read how to test and what mitigation costs.