Missouri has 108 counties, with 11 classified as EPA Zone 1 (highest risk). With an average radon level of 7.15 pCi/L, Missouri state testing data reveals significantly elevated risks across multiple counties. Testing is highly recommended.
Missouri is the 21st most expansive state in terms of size and the 18th most populous in the entire US.
Missouri 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.
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 |
|---|---|---|
| Troy | 8.50 pCi/L | 4 |
| Lees Summit | 7.00 pCi/L | 3 |
| Columbia | 3.00 pCi/L | 2 |
| House Springs | 7.00 pCi/L | 1 |
| Kansas City | 7.00 pCi/L | 1 |
| Springfield | 7.00 pCi/L | 1 |
| Independence | 5.00 pCi/L | 1 |
| Wentzville | No submissions | 0 |
All 108 Missouri counties with their EPA radon zone classification and user-submitted average radon levels.
Browse radon data for individual cities across Missouri. Each city page includes user-submitted radon levels, local contractors, and mitigation resources.