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Radon Levels in Kandiyohi County, Minnesota

EPA puts Kandiyohi County in Zone 1, its highest radon zone, and high results are common there: 65.1% of the 106 radon tests reported to CDC (2023) came back at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    65.1%

    30.5 pts above MN

    Kandiyohi
    65.1%
    Minnesota
    34.6%

    106 tests, 2023

  • Median result

    5.3pCi/L

    Action level reached

    Kandiyohi
    5.3 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    106

    31st of 62 by tests

    Kandiyohi
    106
    Hennepin
    6,545

    Reported to CDC before any fix, 2023

  • EPA radon zone

    Zone 1

    Highest potential

    1. Zone 1
    2. 2
    3. 3

    1 highest, 3 lowest

    EPA predicts over 4 pCi/L indoors

  • Rank in Minnesota

    5 of 62

    Top quarter

    Kandiyohi
    65.1%
    Renville
    75.7%

    By share, of 62 with 30+ tests

Read a result for Kandiyohi County

Starts at Kandiyohi County's median, 5.3 pCi/L

5.3pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 5.3 pCi/L

At or above 4 pCi/L

  1. Under 20 to 1.9 pCi/L
  2. 2 to 4consider a fix
  3. 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. Kandiyohi County's median reported result, 2023.

Interpret this readingWhat a fix costs

The data

Kandiyohi County, At a glance

Kandiyohi County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Kandiyohi County in and predicts an average indoor of greater than 4 pCi/L (greater than 150 Bq/m³) across the county. That is one forecast for the whole county, not a reading of any address in it; homes above EPA's turn up in all three zones.

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 Kandiyohi County, 2023

Share of reported tests at or above 4 pCi/L, by year, Kandiyohi County
Share of reported tests at or above 4 pCi/L, by year, Kandiyohi County
YearShare of reported tests at or above 4 pCi/L
201469.7%
201568.0%
201660.8%
201771.7%
201861.1%
201960.6%
202053.8%
202151.9%
202250.5%
202365.1%

2023: 65.1%. Across these years the share ran from 50.5% to 71.7%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 106 tests reported to CDC for Kandiyohi 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).

How to read these figures

Kandiyohi County, Compared

Kandiyohi County radon figures, compared

Calculated by Radon411

More than half: 65.1% of the 106 radon tests reported to CDC for Kandiyohi County in 2023 read at least 4 pCi/L. That places it 5th of 62 Minnesota counties with 30 or more tests for the same period. That is 30.5 points above the 34.6% pooled from 86 Minnesota counties.

The median result, 5.3 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 63.8 pCi/L. The rest split 17.0% under 2 pCi/L and 17.9% from 2 to 4 (Minnesota: 36.6% and 28.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 65.1% share point the same way here.

2 of its 6 bordering counties with figures ran higher, led by Renville County at 75.7%; Swift County reported 41.7%. Statewide for the same period, Renville County reported the highest share (75.7%) and Lake County the lowest (3.8%).

The busiest year on file was 2014, with 294 tests reported; the quietest, 2020, had 91.

Over 10 years of annual figures the share fell 4.6 points, from 69.7% in 2014 to 65.1% in 2023; its peak was 71.7% in 2017. Nationally, every county with a figure for the same period pools to 33.4%; Kandiyohi County sits 31.7 points above it.

Share of reported tests at or above 4 pCi/L by year, Kandiyohi County against Minnesota2014 to 2023, years with 30 or more tests: Kandiyohi County 69.7% to 65.1%, the state's pooled share 34.6% in 2023.
Kandiyohi CountyMinnesota, pooled
Share of reported tests at or above 4 pCi/L by year, Kandiyohi County against Minnesota: data table
YearTestsKandiyohi County, at or above 4 pCi/LMinnesota, pooled
201429469.7%42.9%
201523168.0%43.6%
201619460.8%37.0%
201720571.7%38.2%
201823461.1%38.3%
201912760.6%36.1%
20209153.8%31.8%
202113151.9%33.1%
202218650.5%31.6%
202310665.1%34.6%
Kandiyohi County against Minnesota, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Kandiyohi County
Kandiyohi County10665.1%5.3 pCi/LThis county
Minnesota, pooled86 counties, pooled22,44934.6%Not pooled−30.5 points
United States, pooled642 counties, pooled128,74033.4%Not pooled−31.7 points
Faribault Countyhighest in the state3070.0%8.1 pCi/L+4.9 points
Lake Countylowest in the state783.8%1.3 pCi/L−61.3 points
Renville County, MNborders it3775.7%6.3 pCi/L+10.6 points
Chippewa County, MNborders it3565.7%4.8 pCi/L+0.6 points
Pope County, MNborders it5550.9%4.2 pCi/L−14.2 points
Meeker County, MNborders it5949.2%3.9 pCi/L−15.9 points
Stearns County, MNborders it36646.7%3.7 pCi/L−18.4 points
Swift County, MNborders it3641.7%3.8 pCi/L−23.4 points
Where Kandiyohi County's reported results fell, 2023, beside Minnesota and the United States
ResultKandiyohi County testsKandiyohi County shareMinnesota shareU.S. shareAgainst Minnesota
Under 2 pCi/L1817.0%36.6%41.4%−19.6 points
2 to 4 pCi/L1917.9%28.9%25.2%−11.0 points
4 pCi/L and above6965.1%34.6%33.4%+30.5 points
Kandiyohi County ranked among the 62 Minnesota counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Renville County1 of 623775.7%6.3 pCi/L
Faribault County2 of 623070.0%8.1 pCi/L
Freeborn County3 of 627167.6%5.1 pCi/L
Chippewa County4 of 623565.7%4.8 pCi/L
Kandiyohi County5 of 6210665.1%5.3 pCi/L
Clay County6 of 6210065.0%5.5 pCi/L
Lyon County6 of 628065.0%6.1 pCi/L
Brown County8 of 6211563.5%5.4 pCi/L
Dodge County9 of 6215563.2%4.7 pCi/L
Le Sueur County10 of 6213562.2%5.1 pCi/L
Otter Tail County11 of 6217161.4%4.8 pCi/L
Kandiyohi County radon tests by year, against Minnesota's pooled share
YearTestsAt or above 4 pCi/LMedianHighestMinnesota, pooledChange from the row before
202310665.1%5.3 pCi/L63.8 pCi/L34.6%+14.6 points
202218650.5%4.1 pCi/L22.3 pCi/L31.6%−1.4 points
202113151.9%4.1 pCi/L38.9 pCi/L33.1%−1.9 points
20209153.8%4.3 pCi/L34.3 pCi/L31.8%−6.8 points
201912760.6%5.0 pCi/L33.5 pCi/L36.1%−0.5 points
201823461.1%4.7 pCi/L42.1 pCi/L38.3%−10.6 points
201720571.7%5.7 pCi/L43.1 pCi/L38.2%+10.9 points
201619460.8%5.4 pCi/L108.2 pCi/L37.0%−7.2 points
201523168.0%5.7 pCi/L175.8 pCi/L43.6%−1.7 points
201429469.7%6.0 pCi/L49.6 pCi/L42.9%First on file

Pooled shares: Radon411's sum of CDC's county counts for one period.

Kandiyohi County, State data

Minnesota's own radon test data

Measured

What Minnesota's own agencies publish about radon tests in Kandiyohi 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 Kandiyohi 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

63.9%

785 properties tested with one or more tests at or above 4 pCi/L

Median result

4.8 pCi/L

Average result

6.2 pCi/L

Tests behind these figures

123 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.

Kandiyohi County, Geology

The ground under Kandiyohi County

Predicted

USGS's geologic map puts all of Kandiyohi County's mapped land in one class: high radon potential. The map puts 53.7% of Kandiyohi County in the area it calls Central Lowland-Till Prairie and 46.3% in Central Lowland-Western Lake Section. USGS gives both a radon index of 14, in the high band (12 to 17).

USGS's geologic areas under Kandiyohi County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Central Lowland-Till PrairieSilty and clayey till derived from shale and sandstone.High1453.7%
Central Lowland-Western Lake SectionSandy calcareous till derived from carbonate rocks.High1446.3%

Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.

Kandiyohi County beside the ground around it

Kandiyohi 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; Meeker County comes nearest at 100%.

Share of land by USGS radon potential: Kandiyohi County, the 6 counties bordering it and Minnesota
AreaEPA zoneLow potentialModerate potentialHigh potential
Kandiyohi CountyZone 1NoneNone100%
Meeker CountyZone 1NoneNone100%
Stearns CountyZone 1None21.5%78.5%
Chippewa CountyZone 1NoneNone100%
Swift CountyZone 1NoneNone100%
Renville CountyZone 1NoneNone100%
Pope CountyZone 1NoneNone100%
Minnesota87 counties, pooled by land areaVariesNone38.9%61.1%

The map rates the ground, not the air in any home.

Local help

Kandiyohi County, Local resources

Radon testing and mitigation in Kandiyohi County

Listed radon businesses with an address in Kandiyohi County:

Listed radon professionals by town: Sunburg

What Minnesota's program says
Phone
651-201-4601
Email
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

Kandiyohi County, Questions

Questions about radon in Kandiyohi County

Are radon levels high in Kandiyohi County?

In 2023, 65.1% of the radon tests reported to CDC for Kandiyohi County, Minnesota were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.3 pCi/L. Of 62 Minnesota counties with 30 or more tests for the same period, 4 reported a higher share; pooled, the state comes to 34.6%.

Which counties border Kandiyohi County?

Kandiyohi County borders 6 counties: Meeker County, Stearns County, Chippewa County, Swift County, Renville County and Pope County.

Products

Kandiyohi County, Products

Testing a home in Kandiyohi County

In Kandiyohi County, 65.1% of 106 tests reported to CDC in 2023 reached 4 pCi/L, against 34.6% pooled across Minnesota. In Zone 1 the year-round level in Kandiyohi 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

Kandiyohi County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Kandiyohi County

Explore

Kandiyohi County, Bordering counties

Counties bordering Kandiyohi County

Calculated by Radon411

Kandiyohi County, Cities and towns

Cities and towns in Kandiyohi County

The Census Bureau estimates 44,720 residents in Kandiyohi County for July 1, 2025, 993 more than in 2020 (+2.3%). That works out to 56 people per square mile of land. Its largest town, Willmar, has 22,001 residents, 49.2% of the total. Reported testing is thin here: 106 tests over 2023, or 2.4 for every 1,000 residents (2025 estimate), where Minnesota as a whole comes to 3.9.

From Willmar to Regal, CDC publishes no figure by town: each reads Kandiyohi County's.

The cities and towns in Kandiyohi County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Willmar22,001+4.5%49.2%
New London1,322+4.8%3.0%
Spicer1,096−1.5%2.5%
Atwater1,090−2.8%2.4%
Raymondextends beyond Kandiyohi County789+0.5%Counted whole
Kandiyohi560−2.3%1.3%
Prinsburg507−1.7%1.1%
Pennock478−1.0%1.1%
Lake Lillian246−2.0%0.6%
Blomkest137−4.2%0.3%
Sunburg92−3.2%0.2%
Regal41+2.5%Under 0.1%

12 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 Kandiyohi County is counted whole, so it has no share.

Kandiyohi County, Homes

Homes in Kandiyohi County

Of Kandiyohi County's 20,212 homes, 74% are detached houses, against 66% across Minnesota; 14% are in buildings of five or more homes. Half of its homes were built before 1977, close to Minnesota's 1978: 30% date from before 1960 and 19% from 2000 or later. 72% of occupied homes are lived in by their owner (Minnesota: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Kandiyohi County, Minnesota, 2019 to 2023
HomesKandiyohi CountyMinnesota
Housing units20,2122,519,538
Detached houses74%66%
In buildings of 5 or more14%19%
Mobile homes3%3%
Built before 196030%29%
Built since 200019%22%
Middle year built19771978
Owner-occupied72%72%

Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.