About RadonByZipCode.com
Free radon risk data for every US ZIP code, powered by EPA and CDC sources.
RadonByZipCode.com is a free tool that shows radon risk levels for any US ZIP code. We combine data from two authoritative federal sources to give you a clear picture of radon risk in your area.
Our Data Sources
EPA Map of Radon Zones
The U.S. Environmental Protection Agency classifies every county into three radon zones based on predicted indoor radon levels. Covers all 3,143 US counties.
CDC Tracking Network
Actual radon testing results from the CDC's Environmental Health Tracking Network — homes tested per county and the percentage that exceeded the EPA's 4.0 pCi/L action level.
Important Limitations
Radon levels are highly variable — even neighboring homes can have very different levels depending on soil composition, foundation type, ventilation, and other factors. Our data shows county-level averages and zone classifications. The only way to know the radon level in your specific home is to test it.
Privacy & Terms
We respect your privacy and are committed to transparency. Read our Privacy Policy and Terms of Service for full details.