Radon testing in Rockford, IL
Testing is the only way to know your home's radon level. You can test yourself or hire an IEMA-OHS-licensed measurement professional.
Option 1: test it yourself
- Winnebago County Health Department sells test kits. Call 815-720-4100. The health department says each kit's price includes return postage and certified lab analysis.[1]
- The health department also notes that kits are available at many local hardware and building stores.[1]
- Follow the kit's placement instructions: lowest lived-in level, closed-house conditions, away from drafts.
Option 2: hire a licensed measurement professional
In Illinois, anyone testing for compensation must be licensed by IEMA-OHS.[2] IEMA-OHS recommends professional testing for real-estate transactions.[3] Check the licensee lookup and filter by Winnebago County.
Short-term vs long-term tests
EPA explains that radon levels vary from day to day and season to season, so a short-term test is less likely than a long-term test (over 90 days) to tell you your year-round average.[4]
| Step (EPA) | What to do |
|---|---|
| 1 | Take a short-term test. If the result is 4 pCi/L or higher, take a follow-up test. |
| 2 | Follow up with a long-term test (better year-round picture) or a second short-term test (faster). |
| 3 | Fix the home if the long-term result, or the average of the two short-term results, is 4 pCi/L or more. |
Summarized from EPA's Citizen's Guide.[4]
What your number means
The U.S. EPA action level is 4.0 pCi/L. IEMA-OHS and EPA recommend reducing radon at or above it.[3] EPA also says levels below 4 pCi/L still pose some risk, and it suggests considering a fix between 2 and 4 pCi/L.[4]
Rockford-area data
Winnebago County is in EPA Radon Zone 1.[5] IEMA-OHS publishes licensee-reported measurements. Our tally of that data for Winnebago County (Nov 14, 2026) found 8,595 tests, with 3,140 (about 37%) at or above 4 pCi/L. The dataset doesn't state the years it covers.[6] Homes next door to each other can differ, so test your own home.
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Sources
- Winnebago County Health Department, Radon
- Radon Industry Licensing Act, 420 ILCS 44 (Sec. 25 license requirement)
- IEMA-OHS, “What is Radon?” (cost, fan energy, action level, SSD)
- U.S. EPA, “A Citizen’s Guide to Radon” (PDF)
- U.S. EPA, Map of Radon Zones (PDF)
- IEMA-OHS radon results dashboard (public measurement data; Winnebago counts tallied Nov 14, 2026)
- IEMA, “Radon Testing Guidelines for Real Estate Transactions” (PDF)
Sources reviewed November 14, 2026.