Radon levels in Hawaii

Hawaii is outside the national model's coverage (conterminous US only), so this page shows the EPA radon zone for each county. Zones are a 1993 county-level classification, not a measurement.

Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.

0 / 5

EPA Zone 1 counties (0%)

0 / 5

Zone 2 / Zone 3 counties

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counties predicted ≥ 4 pCi/L

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of ZIP codes predicted ≥ 4 pCi/L

What the data says about radon in Hawaii

Hawaii is outside the conterminous US, so the Harvard/Emory national model publishes no ZIP-level predictions for it and this page cannot report a predicted average. What can be said from the data: 0 of 5 counties are EPA Zone 1, 0 Zone 2 and 5 Zone 3. A uniform Zone 3 rating means the EPA expected screening averages under 2 pCi/L everywhere in the state, but that is a 1993 prediction, not a measurement, and individual homes are not covered by it.

Hawaii counties by predicted radon

Sorted highest to lowest predicted basement average (model estimate). 5 counties.

CountyPredicted basementUpstairsGradeEPA zoneZIPs
Hawaii Countyn/a-zone onlyEPA Zone 30
Honolulu Countyn/a-zone onlyEPA Zone 30
Kalawao Countyn/a-zone onlyEPA Zone 30
Kauai Countyn/a-zone onlyEPA Zone 30
Maui Countyn/a-zone onlyEPA Zone 30

Radon levels in Hawaii cities

The 3 most-populous Hawaii places among the 1,000 largest US cities (Census incorporated places and CDPs), by population. City figures are ZIP-land-weighted means of the model's ZIP predictions (model estimate).

CityPopulationPredicted basementUpstairsGradeZIPs ≥ 4
Honolulu341,778n/a-zone only-
East Honolulu49,914n/a-zone only-
Pearl City47,698n/a-zone only-

Hawaii radon questions

Why are there no predicted radon values for Hawaii?
The National Radon Exposure Model covers the conterminous United States only, so Hawaii has no ZIP-level predictions. Each Hawaii county is shown with its EPA radon zone (0 Zone 1, 0 Zone 2, 5 Zone 3). Testing is the only way to know a home's level.

Hawaii radon program

State programs keep lists of certified testers and mitigators and sometimes run kit programs. We link only pages we could verify, and Hawaii's program page did not respond when we checked, so start from the EPA state radon contacts page. Then read how to test and what mitigation costs.