Arizona has 15 counties, with 0 classified as EPA Zone 1 (highest risk). With an average radon level of 6.29 pCi/L, Arizona state testing data reveals significantly elevated risks across multiple counties. Testing is highly recommended.
Arizona is the sixth largest state in the US, and the 15th most populous. From the years 1987-89 statewide surveys were conducted by the Arizona Radiation Regulatory Agency, and they found that nearly 1 out of every 15 Arizona homes contained elevated radon levels above the recommended action level. When compared to the US national average those numbers are pretty close.
The state has a well maintained Radon program, with a wide variety of resources and information available on the official site.
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.
All 15 Arizona counties with their EPA radon zone classification and user-submitted average radon levels.
Browse radon data for individual cities across Arizona. Each city page includes user-submitted radon levels, local contractors, and mitigation resources.