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Radon Levels in Redwood County, Minnesota

EPA puts Redwood County in Zone 1, its highest radon zone, and high results are common there: 54.8% of the 31 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

    54.8%

    20.2 pts above MN

    Redwood
    54.8%
    Minnesota
    34.6%

    31 tests, 2023

  • Median result

    4.6pCi/L

    Action level reached

    Redwood
    4.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    31

    60th of 62 by tests

    Redwood
    31
    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

    17 of 62

    Middle half

    Redwood
    54.8%
    Renville
    75.7%

    By share, of 62 with 30+ tests

Read a result for Redwood County

Starts at Redwood County's median, 4.6 pCi/L

4.6pCi/L

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

EPA’s reading of 4.6 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. Redwood County's median reported result, 2023.

Interpret this readingWhat a fix costs

The data

Redwood County, At a glance

Redwood County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Redwood 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 Redwood County, 2023

Share of reported tests at or above 4 pCi/L, by year, Redwood County
Share of reported tests at or above 4 pCi/L, by year, Redwood County
YearShare of reported tests at or above 4 pCi/L
201477.1%
201564.8%
201661.4%
201753.8%
201876.5%
201938.9%
202043.6%
202165.3%
202219.4%
202354.8%

2023: 54.8%. Across these years the share ran from 19.4% to 77.1%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 31 tests reported to CDC for Redwood 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

Redwood County, Compared

Redwood County radon figures, compared

Calculated by Radon411

More than half: 54.8% of the 31 radon tests reported to CDC for Redwood County in 2023 read at least 4 pCi/L. That places it 17th of 62 Minnesota counties with 30 or more tests for the same period. That is 20.2 points above the 34.6% pooled from 86 Minnesota counties.

The median result, 4.6 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 34.6 pCi/L. The rest split 35.5% under 2 pCi/L and 9.7% from 2 to 4 (Minnesota: 36.6% and 28.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 54.8% share point the same way here.

All 3 of its bordering counties with figures ran higher, led by Renville County at 75.7%; the lowest of them, Brown County, reported 63.5%. 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 2022, with 170 tests reported; the quietest, 2017, had 26.

Over 9 years of annual figures the share fell 22.3 points, from 77.1% in 2014 to 54.8% in 2023; its peak was 77.1% in 2014. Nationally, every county with a figure for the same period pools to 33.4%; Redwood County sits 21.4 points above it.

Share of reported tests at or above 4 pCi/L by year, Redwood County against Minnesota2014 to 2023, years with 30 or more tests: Redwood County 77.1% to 54.8%, the state's pooled share 34.6% in 2023.
Redwood CountyMinnesota, pooled
Share of reported tests at or above 4 pCi/L by year, Redwood County against Minnesota: data table
YearTestsRedwood County, at or above 4 pCi/LMinnesota, pooled
20147077.1%42.9%
20158864.8%43.6%
20164461.4%37.0%
20183476.5%38.3%
20193638.9%36.1%
20203943.6%31.8%
20214965.3%33.1%
202217019.4%31.6%
20233154.8%34.6%
Redwood County against Minnesota, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Redwood County
Redwood County3154.8%4.6 pCi/LThis county
Minnesota, pooled86 counties, pooled22,44934.6%Not pooled−20.2 points
United States, pooled642 counties, pooled128,74033.4%Not pooled−21.4 points
Faribault Countyhighest in the state3070.0%8.1 pCi/L+15.2 points
Lake Countylowest in the state783.8%1.3 pCi/L−51.0 points
Renville County, MNborders it3775.7%6.3 pCi/L+20.9 points
Yellow Medicine County, MNborders it1973.7%7.8 pCi/L+18.9 points
Murray County, MNborders it2572.0%8.1 pCi/L+17.2 points
Lyon County, MNborders it8065.0%6.1 pCi/L+10.2 points
Brown County, MNborders it11563.5%5.4 pCi/L+8.7 points
Cottonwood County, MNborders it1250.0%3.5 pCi/L−4.8 points
Where Redwood County's reported results fell, 2023, beside Minnesota and the United States
ResultRedwood County testsRedwood County shareMinnesota shareU.S. shareAgainst Minnesota
Under 2 pCi/L1135.5%36.6%41.4%−1.1 points
2 to 4 pCi/L39.7%28.9%25.2%−19.2 points
4 pCi/L and above1754.8%34.6%33.4%+20.2 points
Redwood 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
Waseca County12 of 626360.3%5.0 pCi/L
Polk County13 of 629060.0%4.7 pCi/L
Sibley County13 of 625560.0%5.0 pCi/L
Nobles County15 of 624158.5%4.7 pCi/L
McLeod County16 of 6213155.7%4.7 pCi/L
Redwood County17 of 623154.8%4.6 pCi/L
Fillmore County18 of 6211853.4%4.2 pCi/L
Jackson County19 of 624452.3%4.1 pCi/L
Becker County20 of 624652.2%4.1 pCi/L
Steele County21 of 6214051.4%4.0 pCi/L
Pope County22 of 625550.9%4.2 pCi/L
Redwood County radon tests by year, against Minnesota's pooled share
YearTestsAt or above 4 pCi/LMedianHighestMinnesota, pooledChange from the row before
20233154.8%4.6 pCi/L34.6 pCi/L34.6%+35.4 points
202217019.4%0.7 pCi/L16.6 pCi/L31.6%−45.9 points
20214965.3%5.1 pCi/L26.7 pCi/L33.1%+21.7 points
20203943.6%3.7 pCi/L38.0 pCi/L31.8%+4.7 points
20193638.9%2.9 pCi/L23.2 pCi/L36.1%−37.6 points
20183476.5%6.4 pCi/L32.3 pCi/L38.3%+22.7 points
20172653.8%5.3 pCi/L18.4 pCi/L38.2%−7.6 points
20164461.4%5.0 pCi/L16.3 pCi/L37.0%−3.4 points
20158864.8%6.3 pCi/L53.0 pCi/L43.6%−12.3 points
20147077.1%6.6 pCi/L52.2 pCi/L42.9%First on file

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

Redwood County, State data

Minnesota's own radon test data

Measured

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

64.7%

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

Median result

5.1 pCi/L

Average result

6.2 pCi/L

Tests behind these figures

44 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.

Redwood County, Geology

The ground under Redwood County

Predicted

USGS's geologic map puts all of Redwood 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).

USGS's geologic areas under Redwood County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Central Lowland-Till PrairieSilty and clayey till derived from shale and sandstone.High14100%

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

Redwood County beside the ground around it

Redwood 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%.

Share of land by USGS radon potential: Redwood County, the 6 counties bordering it and Minnesota
AreaEPA zoneLow potentialModerate potentialHigh potential
Redwood CountyZone 1NoneNone100%
Renville CountyZone 1NoneNone100%
Cottonwood CountyZone 1NoneNone100%
Brown CountyZone 1NoneNone100%
Lyon CountyZone 1NoneNone100%
Murray CountyZone 1NoneNone100%
Yellow Medicine CountyZone 1NoneNone100%
Minnesota87 counties, pooled by land areaVariesNone38.9%61.1%

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

Local help

Redwood County, Local resources

Radon testing and mitigation in Redwood County

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

Redwood County, Questions

Questions about radon in Redwood County

Are radon levels high in Redwood County?

In 2023, 54.8% of the radon tests reported to CDC for Redwood County, Minnesota were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.6 pCi/L. Of 62 Minnesota counties with 30 or more tests for the same period, 16 reported a higher share; pooled, the state comes to 34.6%.

Which counties border Redwood County?

Redwood County borders 6 counties: Renville County, Cottonwood County, Brown County, Lyon County, Murray County and Yellow Medicine County.

Products

Redwood County, Products

Testing a home in Redwood County

In Redwood County, 54.8% of 31 tests reported to CDC in 2023 reached 4 pCi/L, against 34.6% pooled across Minnesota. In Zone 1 the year-round level in Redwood 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

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

Explore

Redwood County, Bordering counties

Counties bordering Redwood County

Calculated by Radon411

Redwood County, Cities and towns

Cities and towns in Redwood County

About 15,265 people live in Redwood County by the Census Bureau's estimate for July 1, 2025, 152 fewer than in 2020 (−1.0%). That works out to 17 people per square mile of land. Its largest town, Redwood Falls, has 5,040 residents, 33.0% of the total. Together its 15 incorporated places hold 65.1% of those residents; the other 34.9% live outside any of them. Reported testing is thin here: 31 tests over 2023, or 2.0 for every 1,000 residents (2025 estimate), where Minnesota as a whole comes to 3.9.

From Redwood Falls to Delhi, CDC publishes no figure by town: each reads Redwood County's.

The 12 largest cities and towns in Redwood County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Redwood Falls5,040−1.3%33.0%
Morgan881−1.8%5.8%
Lamberton774−2.3%5.1%
Wabasso750+2.0%4.9%
Walnut Grove732−2.3%4.8%
Sanborn316−2.5%2.1%
Belview285−2.1%1.9%
Vesta270−2.2%1.8%
Milroy253−1.6%1.7%
Lucan205−2.8%1.3%
Clements150−2.0%1.0%
Revere88−1.1%0.6%
  • Seaforth
  • Wanda
  • Delhi

15 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).

Redwood County, Homes

Homes in Redwood County

Redwood County is a place of houses on their own lots: 80% of its 7,103 homes are detached single-family houses, against 66% across Minnesota. The homes are older than Minnesota's as a whole: half were built before 1963 (1978 for Minnesota), and 48% date from before 1960. 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 in Redwood County, Minnesota, 2019 to 2023
HomesRedwood CountyMinnesota
Housing units7,1032,519,538
Detached houses80%66%
In buildings of 5 or more9%19%
Mobile homes5%3%
Built before 196048%29%
Built since 20009%22%
Middle year built19631978
Owner-occupied80%72%

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