Hawaii Cities Ranked by Indoor Radon Levels
Measured averages from Airthings devices across Hawaii, USA. Action level: 4 pCi/L — the threshold at which remediation is recommended.
Waimea has the highest measured indoor radon in Hawaii at 1.0 pCi/L, based on Airthings measurements across 2 cities.
Updated August 16, 2026
Highest city
1.0pCi/L
Waimea
Hawaii city average
0.7pCi/L
across 2 cities
Above action level
0/ 2
cities
| # | Location | Avg level | Monitors | vs action level |
|---|---|---|---|---|
| 1 | Waimea | 1.0 pCi/L | 19 | 0.2× under |
| 2 | Honolulu | 0.3 pCi/L | 32 | 0.1× under |