Rankings HawaiiHighest radon potential

Counties with the Highest Radon Potential in Hawaii

The top 5 of 5 Hawaii counties on GIS Map, ranked by EPA radon zone, where zone 1 carries the highest predicted indoor radon potential and zone 3 the lowest.

#	County	EPA radon zone	Population
1	Hawaii County	3	205,769
2	Honolulu County	3	1,001,146
3	Kalawao County	3	67
4	Kauai County	3	73,731
5	Maui County	3	164,522

Source: EPA Map of Radon Zones (September 2025). All counties with data are ranked. Estimates carry margins of error.

Citing this page: GIS Map, “Counties with the Highest Radon Potential in Hawaii”, https://gismap.land/rankings/hawaii/highest-radon-counties. Figures from EPA Map of Radon Zones (September 2025).

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