Radon · Hawaii
Radon in Hawaii
All 5 Hawaii ZIPs zipradar carries sit in Zone 3 (lowest, below 2 pCi/L). The zone is a county-level EPA prediction, not a reading from any building — it narrows the question but does not settle it, and EPA's own guidance is that the only way to know a specific home is an at-home test kit.
Last verified 2026-09-24 · methodology
Radon by ZIP code in Hawaii
EPA's county radon zone for each ZIP zipradar covers. Tap a ZIP for what the zone means and how to test.
| ZIP | EPA radon zone |
|---|---|
| 96813HonoluluHonolulu County | Zone 3 · lowest |
| 96732KahuluiMaui County | Zone 3 · lowest |
| 96720HiloHawaii County | Zone 3 · lowest |
| 96766Lihue (Kauai)Kauai County | Zone 3 · lowest |
| 96793Wailuku (Maui)Maui County | Zone 3 · lowest |
County-level figures from EPA Radon Zones, joined to each ZIP by county. None of them is a measurement at a specific address.
What lands here
Pages show the county zone, what the classification means for home testing recommendations, and state-level supplementary data where available.
Source & refresh
EPA Radon Zones. Refreshed static 1993 baseline plus state-level supplementary updates. Primary source →
Hawaii top concern
Tsunami, lava-zone, water-source isolation
Hawaii's federated data is unusual: FEMA tsunami evacuation zones are state-managed alongside NFHL flood maps; Big Island lava-flow zones (USGS) overlay FEMA hazard layers. Each island operates independent water utilities, so EPA SDWIS PWSIDs do not aggregate across the state.
See Hawaii state page for the full state-level rollup across all 12 dimensions.
Read more on radon
Editorial deep-dives explaining the source data, its limits, and how to read it.
EPA Radon Zones — what 1, 2, and 3 mean and when you should test
EPA classifies every US county into Zone 1 (high), Zone 2 (moderate), or Zone 3 (low) for radon. Plain-English guide to the classifications and at-home testing.
EPA SDWIS — how to read drinking-water violations and what they actually mean
Plain-English guide to EPA SDWIS drinking-water violations: health-based vs. monitoring vs. reporting violations, MCLs, and what triggers a public notice.
Radon and real estate — what disclosure laws and home tests actually require
What home sellers must disclose about radon by state, when home tests are required, and how to interpret radon-mitigation systems if a home you're buying has one.
Radon disclosure during real-estate transactions — state-by-state
Whether sellers must disclose known radon results varies by state. Quick map of mandatory-disclosure states + what to ask for during inspection.