Wyoming has 23 counties, with 21 classified as EPA Zone 1 (highest risk). With an average radon level of 7.87 pCi/L, Wyoming state testing data reveals significantly elevated risks across multiple counties. Testing is highly recommended.
Wyoming is the 10th most expansive in terms of size and the least populous in the entire US. It also happens to be the second least densely populated state in the country.
Wyoming does have an active radon program, dedicated to educating citizens about the risks associated with the deadly gas. You can find more information on Radon, testing and mitigation at the official page.
Cities with the most user-submitted radon test data, ranked by number of submissions.
| City | Avg User Radon Level | Submissions |
|---|---|---|
| Lander | 8.18 pCi/L | 11 |
| Rock Springs | 5.22 pCi/L | 9 |
| Laramie | 5.83 pCi/L | 6 |
| Green River | 12.60 pCi/L | 5 |
| Riverton | 8.40 pCi/L | 5 |
| Casper | 5.60 pCi/L | 5 |
| Sheridan | 10.75 pCi/L | 4 |
| Thayne | 9.25 pCi/L | 4 |
| Cody | 5.75 pCi/L | 4 |
| Cheyenne | 5.00 pCi/L | 4 |
| Thermopolis | 5.00 pCi/L | 3 |
| Gillette | 20.00 pCi/L | 1 |
| Jackson | No submissions | 0 |
All 23 Wyoming counties with their EPA radon zone classification and user-submitted average radon levels.
Browse radon data for individual cities across Wyoming. Each city page includes user-submitted radon levels, local contractors, and mitigation resources.