Radon Levels by State 2025

Average Radon Level (pCi/L)

2.0
4.0
6.0
8.0
10.0
  • Radon levels shown are state-level averages. Within each state, the radon level can vary significantly from one county, municipality, or home site to another.
  • Radon levels are measured in picocuries per liter (pCi/L). One pCi/L represents one trillionth of a curie of radioactivity per liter of air.