District Of Columbia Cities Ranked by Indoor Radon Levels
Measured averages from Airthings devices across District Of Columbia, USA. Action level: 4 pCi/L — the threshold at which remediation is recommended.
Updated August 16, 2026
Highest city
1.1pCi/L
Washington, D.C.
District Of Columbia city average
1.1pCi/L
across 1 city
Above action level
0/ 1
cities
| # | Location | Avg level | Monitors | vs action level |
|---|---|---|---|---|
| 1 | Washington, D.C. | 1.1 pCi/L | 312 | 0.3× under |