Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Cook County, Minnesota
EPA puts Cook County in Zone 2, its middle radon zone, and most reported tests there come back low, though 12.5% of 32 (2023) reached 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
12.5%
22.1 pts below MN
- Cook
- 12.5%
- Minnesota
- 34.6%
32 tests, 2023
Median result
1.8pCi/L
Below action level
- Cook
- 1.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
32
59th of 62 by tests
- Cook
- 32
- Hennepin
- 6,545
Reported to CDC before any fix, 2023
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Minnesota
61 of 62
Lowest quarter
- Cook
- 12.5%
- Renville
- 75.7%
By share, of 62 with 30+ tests
Read a result for Cook County
Starts at Cook County's median, 1.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.8 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Cook County's median reported result, 2023.
The data
Cook County, At a glance
Cook County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Cook County is a
USGS geologic potential: Moderate across 99% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Cook County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 44.8% |
| 2015 | 43.3% |
| 2016 | 39.1% |
| 2017 | 15.6% |
| 2018 | 19.2% |
| 2019 | 28.6% |
| 2020 | 18.7% |
| 2021 | 32.6% |
| 2022 | 35.7% |
| 2023 | 12.5% |
2023: 12.5%. Across these years the share ran from 12.5% to 44.8%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 32 tests reported to CDC for Cook County over 2023, many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Cook County, Compared
Cook County radon figures, compared
Calculated by Radon411Cook County reports fewer high tests than Minnesota overall. 12.5% of its 32 tests in 2023 were at or above 4 pCi/L. That is 22.1 points below the 34.6% pooled from 86 Minnesota counties.
Ordered from highest share down, it comes 61st of 62 Minnesota counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 33.4%; Cook County sits 20.9 points below it.
Lake County, the one bordering county with a figure for the same period, reported 3.8%. Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 12.5% share point the same way here.
Half the tests came in under 1.8 pCi/L and half over it; the single highest reached 10.7 pCi/L. The rest split 53.1% under 2 pCi/L and 34.4% from 2 to 4 (Minnesota: 36.6% and 28.9%). Year by year, 2014 opened at 44.8% and 2023 closed at 12.5% (down 32.3 points), with 2014 the high at 44.8%.
The busiest year on file was 2020, with 75 tests reported; the quietest, 2018, had 26.
Cook CountyMinnesota, pooled
12.5% % of tests34.6% % of tests
| Year | Tests | Cook County, at or above 4 pCi/L | Minnesota, pooled |
|---|---|---|---|
| 2014 | 58 | 44.8% | 42.9% |
| 2015 | 60 | 43.3% | 43.6% |
| 2016 | 46 | 39.1% | 37.0% |
| 2017 | 32 | 15.6% | 38.2% |
| 2020 | 75 | 18.7% | 31.8% |
| 2021 | 46 | 32.6% | 33.1% |
| 2022 | 70 | 35.7% | 31.6% |
| 2023 | 32 | 12.5% | 34.6% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Cook County, State data
Minnesota's own radon test data
MeasuredWhat Minnesota's own agencies publish about radon tests in Cook County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What the Minnesota Department of Health reports for Cook County
Radon Testing (MN Public Health Data Access Portal): home radon tests reported voluntarily by private laboratories and licensed radon measurement professionals, counted by property. Period: 2016-2025.
Share with one or more tests at or above 4 pCi/L
40.6%
156 properties tested with one or more tests at or above 4 pCi/L
Median result
2.9 pCi/L
Average result
4.8 pCi/L
Tests behind these figures
38 properties tested a year on average
- MDH says these data do not include all of the radon tests conducted in Minnesota.
- Post-mitigation tests are excluded from the averages and the median; the percentages use each property's highest test.
- Each home is unique and can have very different results than a neighbor's home; the only way to know is to test.
- These figures describe tests reported to the Minnesota Department of Health in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.
Measured: Minnesota Department of Health data, 2016-2025.
Cook County, Geology
The ground under Cook County
PredictedUSGS's geologic map puts all of Cook County's mapped land in one class: moderate radon potential. 99.5% of it lies in the area the map calls Superior Upland/Central Lowland-Western Lake Section, to which USGS gives a radon index of 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Superior Upland/Central Lowland-Western Lake Section | Glacial deposits derived primarily from volcanic rock. | Moderate | 10 | 99.5% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Cook County beside the ground around it
Across Minnesota 61.1% of the land is rated high; none of Cook County's is. Lake County, the one county that borders it, has more moderate-potential ground: 99.9%.
The map rates the ground, not the air in any home.
Local help
Cook County, Local resources
Radon testing and mitigation in Cook County
Listed radon businesses with an address in Cook County:
- MDH Indoor Air UnitMDH Indoor Air Unit, run by MN Dept. of Health, licenses or certifies radon professionals and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Minnesota.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 Minnesota255 professionals are listed in Minnesota.
Listed radon professionals by town: Grand Marais
What Minnesota's program says
- Phone
- 651-201-4601
- health.indoorair@state.mn.us
- Licensing of radon professionals
The Radon Licensing Act requires anyone who performs a radon test or radon mitigation, in a building they do not own or lease, must be licensed by MDH.
- Disclosure when a home is sold or rented
The Minnesota Radon Awareness Act requires specific disclosure and education be provided to potential home buyers during residential real estate transactions in Minnesota.
What it means
Cook County, Questions
Questions about radon in Cook County
Are radon levels high in Cook County?
In 2023, 12.5% of the radon tests reported to CDC for Cook County, Minnesota were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.8 pCi/L. Of 62 Minnesota counties with 30 or more tests for the same period, 60 reported a higher share; pooled, the state comes to 34.6%.
Which counties border Cook County?
Cook County borders 1 county: Lake County.
Products
Cook County, Products
Testing a home in Cook County
In Cook County, 12.5% of 32 tests reported to CDC in 2023 reached 4 pCi/L, against 34.6% pooled across Minnesota. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Cook County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Monitor
EcoQube Flex battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 15 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Cook County, Bordering counties
Counties bordering Cook County
Calculated by Radon411- Radon levels in Lake CountyEPA zone 2
3.8%at or above 4 pCi/L
Median 1.3 pCi/L · 78 tests · 8.7 points below Cook County
Cook County, Cities and towns
Cities and towns in Cook County
About 5,522 people live in Cook County by the Census Bureau's estimate for July 1, 2025, 76 fewer than in 2020 (−1.4%). Spread over its land, that is 3.8 people to the square mile. Grand Marais, its one incorporated place, has 1,290 residents, 23.4% of the total. Testing is reported here more often than across the state: CDC's 32 reported tests for 2023 come to 5.8 for every 1,000 residents (2025 estimate), against 3.9 for Minnesota.
Grand Marais is the one incorporated place here; CDC publishes no figure by town, so it reads Cook County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Grand Marais | 1,290 | −3.7% | 23.4% |
One incorporated place, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Cook County, Homes
Homes in Cook County
Cook County is a place of houses on their own lots: 88% of its 6,024 homes are detached single-family houses, against 66% across Minnesota. Much of Cook County is recent building: 30% of its homes have gone up since 2000 and the middle year built is 1986, against 1978 for Minnesota. Owners live in 80% of the occupied homes (Minnesota: 72%), so for most households a test and a fix are their own to order.
| Homes | Cook County | Minnesota |
|---|---|---|
| Housing units | 6,024 | 2,519,538 |
| Detached houses | 88% | 66% |
| In buildings of 5 or more | 4% | 19% |
| Mobile homes | 1% | 3% |
| Built before 1960 | 23% | 29% |
| Built since 2000 | 30% | 22% |
| Middle year built | 1986 | 1978 |
| Owner-occupied | 80% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.