January is National Radon Action Month — designated by the EPA, the US Surgeon General, and the American Lung Association as the month when Americans should test their homes for radon. In Iowa, where roughly 5 in 7 homes test above the EPA action level, January isn't just symbolic. It's when test conditions are most accurate and when free or reduced-cost kits are most widely available.
Why January is the right month to test for radon
Radon test conditions matter. EPA recommends testing under "closed-house conditions" — meaning windows and doors closed for at least 12 hours before and during the test. January in Iowa naturally satisfies this: nobody opens windows in -10°F weather. The cold-winter stack effect (heated indoor air rising creates negative pressure in basements that pulls soil gas including radon indoors) is also maximized in January.
This combination means a January test typically returns the home's highest realistic radon level. If you test elevated in January, you've identified the worst case. If you test low in January, you can confidently conclude the home is below the action level year-round.
Iowa winter radon readings typically test 30-50% higher than summer readings. Testing in summer can give a falsely reassuring result. For the geology + climate background on why Iowa's radon problem is so pronounced, see Why Iowa Has the Highest Indoor Radon in the United States.
Free + reduced-cost Iowa radon test kit programs
Iowa has multiple free or low-cost kit programs running annually, with concentrated availability in January:
Iowa HHS Radon Program
The Iowa Department of Health and Human Services Radon Program (515-281-4928) sometimes distributes free short-term test kits to Iowa residents during Radon Action Month, prioritizing households with elevated risk factors (smokers, families with children, residents of high-radon counties). Check hhs.iowa.gov in late December or early January for the current year's program details.
American Lung Association Iowa Chapter
ALA's national radon program partners with state agencies to distribute discounted test kits through lung.org/radon. Some kits are subsidized to as low as $10 (vs. $25-30 retail). The ALA Iowa Chapter (lung.org/ia) periodically announces local distribution events.
Iowa Cancer Consortium
The Iowa Cancer Consortium (canceriowa.org) is the state's cancer prevention coalition. They coordinate periodic radon awareness campaigns including bulk test kit distribution to community health centers, libraries, and public health departments in Iowa's high-radon counties.
Hardware store + AARST-listed labs
If free kit programs aren't available, charcoal canister test kits at Iowa hardware stores (Home Depot, Lowes, Menards, Ace) typically run $15-30. AARST-NRPP-listed measurement labs (Air Chek, RTCA, Alpha Energy) accept mail-in canisters and provide certified results — these are the same kits health-department programs distribute.
How to test properly
If you're using a short-term charcoal canister:
- Place in the lowest livable level of your home (usually the basement)
- 3+ feet from exterior walls, 1+ foot above the floor
- Away from drafts, windows, doors, HVAC supply vents
- Closed-house conditions (windows + doors shut) for 12+ hours before and during
- Expose for 48-96 hours
- Mail back to the lab within 24 hours of pickup
- Result returns in 5-10 business days
What to do with your result
Once your result returns, use our Iowa Radon Calculator to instantly map your reading against EPA guidance. The three EPA tiers:
- Below 2.0 pCi/L — No action needed. Re-test every 2 years.
- 2.0-3.9 pCi/L — EPA "consider mitigating" zone. Especially if you have smokers, children, or basement bedrooms.
- 4.0+ pCi/L — EPA action level. Install an active radon mitigation system. Choose an NRPP + IDPH-certified Iowa mitigator.
For a deep dive on interpreting your test result — including troubleshooting common test errors — see our Radon Test Results Guide.
If you're under contract on an Iowa home
If you're buying or selling and the inspection radon test comes back elevated, see our Iowa Real Estate Closing Radon Contingency Playbook for the negotiation patterns and timeline.
Sources: EPA Indoor Radon Quality Assurance Plan (EPA 402-R-92-004), Iowa HHS Radon Program, American Lung Association radon program (lung.org/radon), Iowa Cancer Consortium.