Radon levels in Wyoming: Moderate
The model predicts a population-weighted basement average of 3.0 pCi/L across Wyoming's 23 counties - about 1.7× the US average of 1.8 pCi/L. Above-ground floors average 2.1 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.
21 / 23
EPA Zone 1 counties (91%)
2 / 0
Zone 2 / Zone 3 counties
1
counties predicted ≥ 4 pCi/L
2.9%
of ZIP codes predicted ≥ 4 pCi/L
Wyoming counties by predicted radon
Sorted highest to lowest predicted basement average. 23 counties.
| County | Predicted basement | Upstairs | Grade | EPA zone | ZIPs |
|---|---|---|---|---|---|
| Lincoln County | 4.1 pCi/L | 2.6 | High | EPA Zone 1 | 11 |
| Sheridan County | 3.9 pCi/L | 2.6 | Moderate | EPA Zone 1 | 8 |
| Weston County | 3.9 pCi/L | 2.6 | Moderate | EPA Zone 2 | 3 |
| Converse County | 3.6 pCi/L | 2.4 | Moderate | EPA Zone 1 | 4 |
| Fremont County | 3.3 pCi/L | 2.5 | Moderate | EPA Zone 1 | 10 |
| Crook County | 3.3 pCi/L | 2.1 | Moderate | EPA Zone 1 | 6 |
| Big Horn County | 3.2 pCi/L | 2.2 | Moderate | EPA Zone 1 | 9 |
| Teton County | 3.2 pCi/L | 2.4 | Moderate | EPA Zone 1 | 6 |
| Park County | 3.2 pCi/L | 2.3 | Moderate | EPA Zone 1 | 4 |
| Natrona County | 3.1 pCi/L | 2.2 | Moderate | EPA Zone 1 | 6 |
| Hot Springs County | 3.1 pCi/L | 2.4 | Moderate | EPA Zone 1 | 2 |
| Niobrara County | 3.0 pCi/L | 1.8 | Moderate | EPA Zone 1 | 4 |
| Carbon County | 3.0 pCi/L | 2.2 | Moderate | EPA Zone 1 | 9 |
| Campbell County | 3.0 pCi/L | 2.0 | Moderate | EPA Zone 1 | 7 |
| Sweetwater County | 2.8 pCi/L | 2.1 | Moderate | EPA Zone 1 | 6 |
| Johnson County | 2.8 pCi/L | 1.8 | Moderate | EPA Zone 1 | 2 |
| Sublette County | 2.8 pCi/L | 2.2 | Moderate | EPA Zone 1 | 6 |
| Uinta County | 2.7 pCi/L | 1.8 | Moderate | EPA Zone 1 | 2 |
| Washakie County | 2.7 pCi/L | 2.1 | Moderate | EPA Zone 1 | 2 |
| Platte County | 2.6 pCi/L | 1.8 | Moderate | EPA Zone 2 | 5 |
| Goshen County | 2.6 pCi/L | 1.9 | Moderate | EPA Zone 1 | 8 |
| Laramie County | 2.5 pCi/L | 1.8 | Moderate | EPA Zone 1 | 9 |
| Albany County | 2.4 pCi/L | 2.0 | Moderate | EPA Zone 1 | 8 |
Wyoming radon questions
- Is radon high in Wyoming?
- Wyoming's population-weighted predicted basement average is 3.0 pCi/L, about 1.7× the US average of 1.8. 1 of its 23 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 22 are in the 2-4 "consider fixing" range and 0 are below 2. 2.9% of Wyoming ZIP codes are predicted at 4 or higher.
- Which Wyoming county has the highest radon?
- Lincoln County has the highest predicted basement average in Wyoming at 4.1 pCi/L (EPA Zone 1). The lowest is Albany County at 2.4 pCi/L. These are modeled area averages; individual homes in any county can test far higher.
- How many EPA Zone 1 counties are in Wyoming?
- 21 of Wyoming's 23 counties (91%) are EPA Zone 1 (highest potential), 2 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 Wyoming?
- Yes - with some urgency. Wyoming'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.
Wyoming radon program
Many states offer free or discounted test kits and keep lists of certified mitigators. Find the Wyoming radon office through the EPA state radon contacts page. Then read how to test and what mitigation costs.