Does radon mitigation work?

Yes. Properly installed systems typically reduce radon levels significantly. Post-mitigation testing confirms performance.

Radon Levels, Testing and Mitigation in Hawaii

Q: What radon level is considered high?

The EPA action level is 4.0 pCi/L. Many homeowners also choose to fix levels between 2.0 and 4.0 pCi/L.

Q: How much does radon mitigation cost in Hawaii?

Radon mitigation typically costs between $800 and $2,500 depending on foundation type and severity.

Hawaii has 5 counties, with 0 classified as EPA Zone 1 (highest risk). With an average radon level of 2.4 pCi/L, Hawaii state testing data reveals significantly elevated risks across multiple counties. Testing is highly recommended.

Hawaii is the eighth smallest state and the eleventh least populous. Oddly enough, it happens to be the 13th most densely populated out of the entire US.

The state does not have a dedicated radon program. You can find more information on radon, testing and mitigation here at RadonResources.com.

2.4

Avg. pCi/L

Counties

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Zone 1 Counties

Hawaii Radon Map

Zone 1 — High

Zone 2 — Moderate

Zone 3 — Low

Hawaii Metro Areas

Explore radon data organized by metro region, including average levels, hotspot cities, and local mitigation professionals.

Most Active Radon Markets in Hawaii

Cities with the most user-submitted radon test data, ranked by number of submissions.

City	Avg User Radon Level	Submissions
Honolulu	No submissions	0

Hawaii Counties by EPA Radon Zone

All 5 Hawaii counties with their EPA radon zone classification and user-submitted average radon levels.

Zone 3 — Low Risk

Predicted avg. indoor levels < 2 pCi/L

Zone 3 5 counties

Hawaii County Zone 3

Avg: —

Honolulu County Zone 3

Avg: —

Kalawao County Zone 3

Avg: —

Kauai County Zone 3

Avg: —

Maui County Zone 3

Avg: —

Hawaii Cities & Towns

Browse radon data for individual cities across Hawaii. Each city page includes user-submitted radon levels, local contractors, and mitigation resources.

Aiea Camp H M Smith Captain Cook Ewa Beach Fort Shafter Haiku Haleiwa Hana Hauula Hilo Holualoa Honokaa Honolulu J B P H H Kaaawa Kahuku Kahului Kailua Kailua Kona Kalaheo Kamuela Kaneohe Kapaa Kapolei Kaunakakai Keaau Kealakekua Kihei Kilauea Koloa Kula Kurtistown Lahaina Laie Lihue M C B H Kaneohe Bay Makawao Mililani Mountain View Naalehu Pahoa Paia Papaikou Pearl City Pepeekeo Princeville Schofield Barracks Tripler Army Medical Center Wahiawa Waialua Waianae Waikoloa Wailuku Waimanalo Waipahu Wheeler Army Airfield

Frequently Asked Questions About Radon in Hawaii

What radon level is considered "high"?

The EPA action level is 4.0 pCi/L — many homeowners also choose to fix levels between 2.0 and 4.0 pCi/L. Any home with levels at or above 4.0 pCi/L should be mitigated.

How much does radon mitigation cost in Hawaii?

Radon mitigation typically costs between $800 and $2,500, depending on foundation type and radon severity. A standard sub-slab depressurization system usually falls in the $1,000–$1,500 range.

Does mitigation actually work?

Yes — properly installed systems typically reduce radon levels by up to 99%. A post-mitigation test confirms the system is working correctly, and many homeowners re-test periodically.

Should I test again after mitigation?

Yes. A post-mitigation test is the proof your system is working. The EPA recommends testing within 30 days of installation and retesting every two years.

What EPA Radon Zone is my Hawaii county in?

Hawaii counties are classified into three EPA Radon Zones. Zone 1 (highest risk, >4 pCi/L) indicates the most concern. Zone 2 (moderate, 2–4 pCi/L) and Zone 3 (lowest, <2 pCi/L) round out the classification. Use the county directory above to find your specific county's zone and data.

Radon Levels, Testing and Mitigation in Hawaii

Hawaii Radon Map

Hawaii Metro Areas

Most Active Radon Markets in Hawaii

Hawaii Counties by EPA Radon Zone

Hawaii Cities & Towns

Frequently Asked Questions About Radon in Hawaii

Get a Free Radon Quote for Your Hawaii Home

Free Radon Mitigation Quote

Free Radon Mitigation Quote