Maui County, HI radon potential

Maui County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Maui County in the 28th percentile nationally for radon potential — higher than 28% of the counties EPA has rated.

Maui County by the numbers

Maui County, Hawaii is home to about 163,688 people across 1,161.54 square miles. Averaged across its land area, Maui County runs about 141 people per square mile. Within its own EPA zone, Maui County is bigger by population than 85% of the counties that share it. EPA's geology-based Region 9 groups Maui County with 94 other counties nationally sharing its underlying rock and soil profile.

Why the zone isn't the answer by itself

At Zone 3, Maui County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Maui County testing above the action level often enough that skipping a test isn't the safe assumption.

Next steps for a home in Maui County

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Hawaii's state radon program

For Maui County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Maui County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Maui County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Maui County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.