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 4 cities.
Updated August 30, 2026
Highest city
1.0pCi/L
Waimea
Hawaii city average
0.5pCi/L
across 4 cities
Above action level
0/ 4
cities
| # | Location | Avg level | vs action level |
|---|---|---|---|
| 1 | Waimea | 1.0 pCi/L | 0.2× under |
| 2 | Waipi'o Acres | 0.5 pCi/L | 0.1× under |
| 3 | Honolulu | 0.3 pCi/L | 0.1× under |
| 4 | Kailua | 0.3 pCi/L | 0.1× under |