Idaho has 44 counties, with 19 classified as EPA Zone 1 (highest risk). With an average radon level of 8.67 pCi/L, Idaho state testing data reveals significantly elevated risks across multiple counties. Testing is highly recommended.
Idaho is the 14th most expansive state and the 39th most populous. It also happens to be the seventh least densely populated state in the entire US.
The state has a 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 Idaho government page.
Explore radon data organized by metro region, including average levels, hotspot cities, and local mitigation professionals.
Cities with the most user-submitted radon test data, ranked by number of submissions.
| City | Avg User Radon Level | Submissions |
|---|---|---|
| Idaho Falls | 7.29 pCi/L | 7 |
| Hailey | 7.83 pCi/L | 6 |
| Post Falls | 9.00 pCi/L | 5 |
| Coeur D Alene | 9.00 pCi/L | 4 |
| Moscow | 7.75 pCi/L | 4 |
| Victor | 6.67 pCi/L | 3 |
| Driggs | 16.00 pCi/L | 2 |
| Hayden | 8.50 pCi/L | 2 |
| Pocatello | 8.50 pCi/L | 2 |
| Eagle | 6.00 pCi/L | 1 |
| Boise | No submissions | 0 |
| Nampa | No submissions | 0 |
| Sandpoint | No submissions | 0 |
All 44 Idaho counties with their EPA radon zone classification and user-submitted average radon levels.
Browse radon data for individual cities across Idaho. Each city page includes user-submitted radon levels, local contractors, and mitigation resources.