Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Cottonwood County, Minnesota
EPA puts Cottonwood County in Zone 1, its highest radon zone, and only 12 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
68.1%
24.7 pts above MN
- Cottonwood
- 68.1%
- Minnesota
- 43.4%
427 tests, 2008 to 2017
Median result
6.3pCi/L
Action level reached
- Cottonwood
- 6.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
427
46th of 85 by tests
- Cottonwood
- 427
- Hennepin
- 35,213
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Minnesota
12 of 85
Top quarter
- Cottonwood
- 68.1%
- Rock
- 83.8%
By share, of 85 with 30+ tests
Read a result for Cottonwood County
Starts at Cottonwood County's median, 6.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 6.3 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Cottonwood County's median reported result, 2008 to 2017.
The data
Cottonwood County, At a glance
Cottonwood County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Cottonwood County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Cottonwood County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 66.3% |
| 2015 | 79.2% |
| 2016 | 64.7% |
| 2017 | 62.5% |
| 2018 | 51.5% |
| 2019 | 70.4% |
| 2020 | 36.4% |
| 2021 | 53.7% |
| 2022 | 45.8% |
| 2023 | 50.0% |
2023: 50.0%. Across these years the share ran from 36.4% to 79.2%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 12 tests were reported to CDC for Cottonwood County over 2023, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Cottonwood County, Compared
Cottonwood County radon figures, compared
Calculated by Radon411More than half: 68.1% of the 427 radon tests reported to CDC for Cottonwood County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 12th of 85 Minnesota counties with 30 or more tests for the same period. That is 24.7 points above the 43.4% pooled from 87 Minnesota counties.
The newest figure, in 2023, counts only 12 tests (50.0% at or above 4 pCi/L), too few to compare, so this reading uses the 427-test figure.
The median result, 6.3 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 50.1 pCi/L. The rest split 13.6% under 2 pCi/L and 18.3% from 2 to 4 (Minnesota: 27.4% and 29.2%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 68.1% share point the same way here.
5 of its 6 bordering counties with figures ran higher, led by Murray County at 76.4%; Watonwan County reported 62.7%. Statewide for the same period, Rock County reported the highest share (83.8%) and Anoka County the lowest (17.4%).
The busiest year on file was 2015, with 96 tests reported; the quietest, 2023, had 12.
Over 8 years of annual figures the share fell 20.5 points, from 66.3% in 2014 to 45.8% in 2022; its peak was 79.2% in 2015. Nationally, every county with a figure for the same period pools to 35.7%; Cottonwood County sits 32.4 points above it. CDC also counts 63 tests taken after mitigation in Cottonwood County for the same period: tests in homes where a fix was already in.
Cottonwood CountyMinnesota, pooled
45.8% % of tests31.6% % of tests
| Year | Tests | Cottonwood County, at or above 4 pCi/L | Minnesota, pooled |
|---|---|---|---|
| 2014 | 83 | 66.3% | 42.9% |
| 2015 | 96 | 79.2% | 43.6% |
| 2016 | 51 | 64.7% | 37.0% |
| 2017 | 72 | 62.5% | 38.2% |
| 2018 | 66 | 51.5% | 38.3% |
| 2020 | 44 | 36.4% | 31.8% |
| 2021 | 41 | 53.7% | 33.1% |
| 2022 | 48 | 45.8% | 31.6% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Cottonwood County, State data
Minnesota's own radon test data
MeasuredWhat Minnesota's own agencies publish about radon tests in Cottonwood 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 Cottonwood 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
64.6%
235 properties tested with one or more tests at or above 4 pCi/L
Median result
4.9 pCi/L
Average result
6.4 pCi/L
Tests behind these figures
36 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.
Cottonwood County, Geology
The ground under Cottonwood County
PredictedUSGS's geologic map puts all of Cottonwood County's mapped land in one class: high radon potential. All of it lies in the area the map calls Central Lowland-Till Prairie, to which USGS gives a radon index of 14, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Central Lowland-Till Prairie | Silty and clayey till derived from shale and sandstone. | High | 14 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Cottonwood County beside the ground around it
Cottonwood County has more high-potential ground than Minnesota as a whole: 100% of its land against 61.1%. Of the 6 counties that border it, none has as large a share of high-potential ground; Brown County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Cottonwood County, Local resources
Radon testing and mitigation in Cottonwood 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.
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
Cottonwood County, Questions
Questions about radon in Cottonwood County
Are radon levels high in Cottonwood County?
In 2023, 50.0% of the radon tests reported to CDC for Cottonwood County, Minnesota were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.5 pCi/L. Of 85 Minnesota counties with 30 or more tests for the same period, 11 reported a higher share; pooled, the state comes to 43.4%.
Which counties border Cottonwood County?
Cottonwood County borders 6 counties: Jackson County, Watonwan County, Redwood County, Murray County, Brown County and Nobles County.
Products
Cottonwood County, Products
Testing a home in Cottonwood County
In Cottonwood County, 68.1% of 427 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.4% pooled across Minnesota. In Zone 1 the year-round level in Cottonwood County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitor
MonitorKidde
Radon Detector (RAB) battery digital radon detector with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 12 hours
Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Cottonwood County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Cottonwood County
Explore
Cottonwood County, Bordering counties
Counties bordering Cottonwood County
Calculated by Radon411- Radon levels in Murray CountyEPA zone 1
76.4%at or above 4 pCi/L
Median 6.7 pCi/L · 237 tests · 8.3 points above Cottonwood County
- Radon levels in Brown CountyEPA zone 1
73.7%at or above 4 pCi/L
Median 6.7 pCi/L · 1,476 tests · 5.6 points above Cottonwood County
- Radon levels in Nobles CountyEPA zone 1
70.4%at or above 4 pCi/L
Median 7.0 pCi/L · 267 tests · 2.3 points above Cottonwood County
- Radon levels in Redwood CountyEPA zone 1
70.1%at or above 4 pCi/L
Median 6.5 pCi/L · 441 tests · 2.0 points above Cottonwood County
- Radon levels in Jackson CountyEPA zone 1
69.8%at or above 4 pCi/L
Median 6.8 pCi/L · 394 tests · 1.7 points above Cottonwood County
- Radon levels in Watonwan CountyEPA zone 1
62.7%at or above 4 pCi/L
Median 5.3 pCi/L · 292 tests · 5.4 points below Cottonwood County
Cottonwood County, Cities and towns
Cities and towns in Cottonwood County
About 11,405 people live in Cottonwood County by the Census Bureau's estimate for July 1, 2025, 112 fewer than in 2020 (−1.0%). That works out to 18 people per square mile of land. Its largest town, Windom, has 4,817 residents, 42.2% of the total. Testing is reported here more often than across the state: CDC's 427 reported tests for 2008 to 2017 come to 37.4 for every 1,000 residents (2025 estimate), against 22.5 for Minnesota.
From Windom to Bingham Lake, CDC publishes no figure by town: each reads Cottonwood County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Windom | 4,817 | +0.2% | 42.2% |
| Mountain Lake | 1,949 | −2.1% | 17.1% |
| Westbrook | 736 | −2.6% | 6.5% |
| Comfreyextends beyond Cottonwood County | 375 | −2.6% | Counted whole |
| Jeffers | 340 | −3.7% | 3.0% |
| Storden | 215 | −3.6% | 1.9% |
| Bingham Lake | 135 | +2.3% | 1.2% |
7 incorporated places, 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). A place that extends beyond Cottonwood County is counted whole, so it has no share.
Cottonwood County, Homes
Homes in Cottonwood County
Cottonwood County is a place of houses on their own lots: 85% of its 5,163 homes are detached single-family houses, against 66% across Minnesota. The homes are older than Minnesota's as a whole: half were built before 1961 (1978 for Minnesota), and 48% date from before 1960. Owners live in 76% of the occupied homes (Minnesota: 72%), so for most households a test and a fix are their own to order.
| Homes | Cottonwood County | Minnesota |
|---|---|---|
| Housing units | 5,163 | 2,519,538 |
| Detached houses | 85% | 66% |
| In buildings of 5 or more | 7% | 19% |
| Mobile homes | under 1% | 3% |
| Built before 1960 | 48% | 29% |
| Built since 2000 | 7% | 22% |
| Middle year built | 1961 | 1978 |
| Owner-occupied | 76% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.