815 Radon
Rockford, IL
Listed for: Testing
Verified:Illinois state license
Call 815 Radon at (815) 494-8286No website listed
Locations and reports
Radon in Rockford, Illinois
Rockford lies in 2 counties, in EPA Zone 1; 99.1% of it is in Winnebago County, where 34.9% of 2,703 reported tests (2017) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so the only way to know your home's level is to test it.
Data checked By Radon411Methodology
Share at 4+ pCi/L
34.9%
1.2 pts above IL
- Winnebago
- 34.9%
- Illinois
- 33.7%
Winnebago, 51st of 70 in IL, 2017
Median result
2.9pCi/L
Below action level
- Winnebago
- 2.9 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of Winnebago's tests, 2017
Highest county
52.4%
Ogle
- Ogle
- 52.4%
- Winnebago
- 34.9%
2 counties, 2 with 30+ tests, 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
Winnebago; Ogle Zone 1
Tests reported
2,703
In Winnebago
- Winnebago
- 2,703
- Ogle
- 636
Reported to CDC before any fix, 2017
Read a result for Rockford
Starts at Winnebago County's median, 2.9 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.9 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Winnebago County's median reported result, 2017.
The data
Rockford, What is published
What is published for Rockford
Information:
Every figure for Rockford is a county's
Radon data is published by county, not by city, and Rockford reaches into 2 counties: Winnebago County and Ogle County. Each has its own EPA zone and its own CDC test figures, set side by side below and each labelled with its county. Only a test tells you about one home.
Rockford covers 64.5 square miles of land: 99.1% of it lies in Winnebago County and 0.9% in Ogle County. About 147,384 people live there, 2,283 to the square mile.
Rockford, Counties
Rockford's counties, side by side
MeasuredEach county's own EPA zone and its own published CDC figures for 2017, the newest period any of them has. A county without a figure for that period is shown without one, never with a figure from another year.
- Winnebago County
- EPA zone
- Zone 1: Highest predicted potential
- At or above 4 pCi/L
- 34.9%
- Median result
- 2.9 pCi/L
- Tests reported
- 2,703 tests
- Annual years on file
- 4
- Ogle County
- EPA zone
- Zone 1: Highest predicted potential
- At or above 4 pCi/L
- 52.4%
- Median result
- 4.1 pCi/L
- Tests reported
- 636 tests
- Annual years on file
- 4
| County | EPA zone | Reported tests at or above 4 pCi/L | Median reported result | Tests reported | Annual years on file |
|---|---|---|---|---|---|
| Winnebago County | Zone 1: Highest predicted potential | 34.9% | 2.9 pCi/L | 2,703 tests | 4 |
| Ogle County | Zone 1: Highest predicted potential | 52.4% | 4.1 pCi/L | 636 tests | 4 |
Rockford spans 2 counties, each with its own EPA zone and its own CDC figure: Winnebago County (Zone 1, 34.9% of 2,703 tests) and Ogle County (Zone 1, 52.4% of 636 tests).
Winnebago County ranks 51st of 70 Illinois counties with 30 or more tests for that period, 1.2 points above the 33.7% pooled across Illinois's counties, 3.2 points above the national pool of 31.7%. Of the city's other county, Ogle County reported 52.4%.
The counties nearest Rockford with a CDC figure for 2017, measured from the middle of the city: Boone County (13 miles, 46.9% of 525 tests), DeKalb County (29 miles, 41.1% of 1,707 tests) and Stephenson County (31 miles, 57.2% of 519 tests). Across the 8 nearest, the share at or above 4 pCi/L runs from 27.4% to 62.9%; the farthest of them, Lake County, is 55 miles away at 27.4%.
The directory lists 7 businesses with an address in Rockford, 5 for testing and 2 for mitigation. Illinois's other cities with a page of their own: Chicago, Naperville, Springfield and Glenview.
Against Illinois and its other counties
Shares of tests people chose to run and report, by county (2017); the state's is its counties' counts added up, calculated by Radon411. Only a test measures a home.
The counties around Rockford
By distance from the middle of Rockford; counties with 30 or more tests.
The median reported pre-mitigation result for 2017 was 2.9 pCi/L in Winnebago County and 4.1 pCi/L in Ogle County.
Predicted: EPA Map of Radon Zones, by county. Measured: CDC tracking data, by county, 2017.
Rockford, Geology
The ground under Rockford
PredictedUSGS's geologic map puts all of Rockford's mapped land in one class: high radon potential. All of it lies in the area the map calls Galesburg Plain, to which USGS gives a radon index of 13, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Galesburg Plain | Illinoian glacial deposits and loess over Paleozoic sedimentary rocks. | High | 13 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Rockford beside its counties and Illinois
All of Rockford, like all of Winnebago County, is rated high. Rockford has more high-potential ground than Illinois as a whole: 100% of its land against 64.5%.
The map rates the ground, not the air in any home.
Rockford, Homes
Homes in Rockford
Of Rockford's 68,027 homes, 60% are detached houses, against 70% across Winnebago County; 17% are in buildings of five or more homes. The homes are older than Winnebago County's as a whole: half were built before 1962 (1971 for Winnebago County), and 47% date from before 1960. 54% of occupied homes are lived in by their owner (Winnebago County: 65%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Rockford | Winnebago County | Illinois |
|---|---|---|---|
| Housing units | 68,027 | 124,959 | 5,443,501 |
| Detached houses | 60% | 70% | 58% |
| In buildings of 5 or more | 17% | 12% | 22% |
| Mobile homes | 1% | 1% | 2% |
| Built before 1960 | 47% | 36% | 38% |
| Built since 2000 | 7% | 13% | 16% |
| Middle year built | 1962 | 1971 | 1970 |
| Owner-occupied | 54% | 65% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.
Local help
Rockford, Professionals
Radon professionals listed in Rockford
Businesses whose listed city is Rockford, from the state registries and listings in the Radon411 directory, with the same business and certification status the directory shows.
Radon professionals listed in Rockford: 1 of 6
7 listings with Rockford as the city. See radon mitigation and testing in Rockford, or all radon professionals in Illinois.
Rockford, Local resources
Local resources for Rockford
Who to ask in Illinois: its radon program, test kits and professionals.
- IEMA-OHS Radon ProgramRun by Illinois Emergency Management Agency and Office of Homeland Security, phone (800) 325-1245.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- Professionals in Illinois7 listings cover Rockford.
The program's own words on licensing and disclosure are on the Illinois page.
What it means
Rockford, Questions
Questions about radon in Rockford
What radon zone is Rockford in?
Both counties Rockford reaches into (Winnebago County and Ogle County) are in Zone 1, the map's highest class: a predicted county average above 4 pCi/L. EPA zones counties, not cities, so that is the zone for every part of Rockford.
What are radon levels in Rockford?
A high result is no surprise around Rockford: 34.9% of 2,703 tests reported from Winnebago County for 2017 reached 4 pCi/L or more. The median reported result was 2.9 pCi/L. Ogle County reported 52.4% of 636 tests; the counties are kept apart.
Should I test my home in Rockford?
Yes. About 943 of the 2,703 tests reported from Winnebago County were at or above 4 pCi/L. That is about what Illinois as a whole reports (33.7%), and ranks Winnebago County 51st of the 70 Illinois counties with 30 or more tests. No map says which homes those are. How to test a home.
What ground is Rockford built on, as far as radon goes?
USGS's geologic map puts all of Rockford on one named area, "Galesburg Plain", rated high for radon potential, radon index 13.
Is radon higher in the counties around Rockford?
Some are and some are not. Against Winnebago County's 34.9%, 7 of the 8 nearest counties with a figure report more and 1 less, from Lake County (27.4%, 55 miles off) to Carroll County (62.9%, 47 miles off).
Who tests for or fixes radon in Rockford?
Radon411's directory has 7 businesses with an address in Rockford, 5 listed for testing and 2 for mitigation. Every entry names the public list it was taken from. Radon professionals in Rockford.
The answers use the published figures of Winnebago County and Ogle County, the counties Rockford lies in.
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