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Radon Levels in Dickinson County, Iowa

EPA puts Dickinson County in Zone 1, its highest radon zone, and high results are common there: 70.3% of the 831 radon tests reported to CDC (2008 to 2017, laboratory totals) 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

    70.3%

    11.8 pts above IA

    Dickinson
    70.3%
    Iowa
    58.5%

    831 tests, 2008 to 2017

  • Median result

    7.0pCi/L

    Action level reached

    Dickinson
    7.0 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    831

    26th of 99 by tests

    Dickinson
    831
    Polk
    10,945

    Reported to CDC before any fix, 2008 to 2017

  • 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 Iowa

    28 of 99

    Middle half

    Dickinson
    70.3%
    Sioux
    84.2%

    By share, of 99 with 30+ tests

Read a result for Dickinson County

Starts at Dickinson County's median, 7.0 pCi/L

7.0pCi/L

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

EPA’s reading of 7.0 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. Dickinson County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Dickinson County, At a glance

Dickinson County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

EPA puts all of Dickinson 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 Dickinson County, 2008 to 2017, laboratory

Reported results by concentration band, Dickinson County, 2008 to 2017, laboratory
Under 2 pCi/L: 15%2 to 4 pCi/L: 15%4 pCi/L and above: 70%

Of 831 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Dickinson County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L12114.6%
2 to 4 pCi/L12615.2%
4 pCi/L and above58470.3%
What these figures count

These are the 831 tests reported to CDC for Dickinson County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).

How to read these figures

Dickinson County, Compared

Dickinson County radon figures, compared

Calculated by Radon411

More than half: 70.3% of the 831 radon tests reported to CDC for Dickinson County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 28th of 99 Iowa counties with 30 or more tests for the same period. That is 11.8 points above the 58.5% pooled from 99 Iowa counties.

The median result, 7.0 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 95.9 pCi/L. The rest split 14.6% under 2 pCi/L and 15.2% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 70.3% share point the same way here.

4 of its 6 bordering counties with figures ran higher, led by O'Brien County at 81.7%; Osceola County reported 67.2%. Statewide for the same period, Sioux County reported the highest share (84.2%) and Decatur County the lowest (25.9%).

CDC's ten-year totals for Dickinson County went from 676 tests (2005 to 2014) to 831 (2008 to 2017), the share going from 72.3% to 70.3%.

Nationally, every county with a figure for the same period pools to 35.7%; Dickinson County sits 34.6 points above it. CDC also counts 82 tests taken after mitigation in Dickinson County for the same period: tests in homes where a fix was already in.

Dickinson County against Iowa, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Dickinson County
Dickinson County83170.3%7.0 pCi/LThis county
Iowa, pooled99 counties, pooled95,24558.5%Not pooled−11.8 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−34.6 points
Sioux Countyhighest in the state1,98284.2%10.7 pCi/L+13.9 points
Decatur Countylowest in the state8525.9%2.5 pCi/L−44.4 points
O'Brien County, IAborders it65281.7%8.9 pCi/L+11.4 points
Clay County, IAborders it74479.4%9.6 pCi/L+9.1 points
Emmet County, IAborders it42071.0%6.3 pCi/L+0.7 points
Palo Alto County, IAborders it46270.8%5.9 pCi/L+0.5 points
Jackson County, MNborders it39469.8%6.8 pCi/L−0.5 points
Osceola County, IAborders it12267.2%6.8 pCi/L−3.1 points
Where Dickinson County's reported results fell, 2008 to 2017, laboratory, beside Iowa and the United States
ResultDickinson County testsDickinson County shareIowa shareU.S. shareAgainst Iowa
Under 2 pCi/L12114.6%21.8%39.6%−7.2 points
2 to 4 pCi/L12615.2%19.7%24.7%−4.5 points
4 pCi/L and above58470.3%58.5%35.7%+11.8 points
Dickinson County ranked among the 99 Iowa counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Emmet County23 of 9942071.0%6.3 pCi/L
Guthrie County24 of 9925770.8%6.9 pCi/L
Palo Alto County25 of 9946270.8%5.9 pCi/L
Mitchell County26 of 9944470.7%6.4 pCi/L
Poweshiek County27 of 9941970.6%7.2 pCi/L
Dickinson County28 of 9983170.3%7.0 pCi/L
Marshall County29 of 9957070.2%8.2 pCi/L
Humboldt County30 of 9938570.1%7.0 pCi/L
Mills County31 of 9946570.1%6.1 pCi/L
Calhoun County32 of 9950769.8%6.1 pCi/L
Fremont County33 of 9920569.8%7.2 pCi/L
Dickinson County ten-year laboratory totals, against Iowa's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIowa, pooledChange from the row before
2008 to 201783170.3%7.0 pCi/L95.9 pCi/L58.5%−1.5 points
2007 to 201681671.8%7.2 pCi/L95.9 pCi/L58.6%−0.3 points
2006 to 201574872.1%7.0 pCi/L95.9 pCi/L59.4%−0.2 points
2005 to 201467672.3%6.8 pCi/L95.9 pCi/L59.6%First on file

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

Dickinson County, Geology

The ground under Dickinson County

Predicted

USGS's geologic map puts all of Dickinson County's mapped land in one class: high radon potential. The map puts 87.9% of Dickinson County in the area it calls Des Moines Lobe and 12.1% in Loess-Covered Drift Plains. USGS gives the first a radon index of 12 and the second 13, both in the high band (12 to 17).

USGS's geologic areas under Dickinson County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Des Moines LobeCalcareous loamy till derived from shale, limestone, dolomite, sandstone.High1287.9%
Loess-Covered Drift PlainsPre-Illinoian and Illinoian glacial deposits, and loess.High1312.1%

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

Dickinson County beside the ground around it

On high-potential ground Dickinson County is close to Iowa as a whole: 100% of its land against 98.8%. Of the 6 counties that border it, none has as large a share of high-potential ground; Clay County comes nearest at 100%.

Share of land by USGS radon potential: Dickinson County, the 6 counties bordering it and Iowa
AreaEPA zoneLow potentialModerate potentialHigh potential
Dickinson CountyZone 1NoneNone100%
Clay CountyZone 1NoneNone100%
Jackson County, MNZone 1NoneNone100%
Emmet CountyZone 1NoneNone100%
Osceola CountyZone 1NoneNone100%
O'Brien CountyZone 1NoneNone100%
Palo Alto CountyZone 1NoneNone100%
Iowa99 counties, pooled by land areaVariesNone1.2%98.8%

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

Local help

Dickinson County, Local resources

Radon testing and mitigation in Dickinson County

Listed radon businesses with an address in Dickinson County:

Listed radon professionals by town: Spirit Lake, Milford, Lake Park

What Iowa's program says
Phone
(515) 281-4928
Licensing of radon professionals
Iowa’s radon program approves applications for persons who wish to become certified to perform radon testing or credentialed to perform mitigation and laboratories that provide radon testing devices and analytical services.
Disclosure when a home is sold or rented
However, per Iowa Code chapters 543B.9 and 543B.18 and Iowa Administrative Code 193E Chapter 14 administered by the Iowa Real Estate Commission, a seller must disclose any known tests for the presence of radon and if yes, provide the date of last report and the result(s).

What it means

Dickinson County, Questions

Questions about radon in Dickinson County

Are radon levels high in Dickinson County?

Over the 2008 to 2017 laboratory totals, 70.3% of the radon tests reported to CDC for Dickinson County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 7.0 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 27 reported a higher share; pooled, the state comes to 58.5%.

Which counties border Dickinson County?

Dickinson County borders 6 counties: Clay County, IA, Jackson County, MN, Emmet County, IA, Osceola County, IA, O'Brien County, IA and Palo Alto County, IA.

Products

Dickinson County, Products

Testing a home in Dickinson County

In Dickinson County, 70.3% of 831 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 58.5% pooled across Iowa. In Zone 1 the year-round level in Dickinson 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

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

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Dickinson County, Bordering counties

Counties bordering Dickinson County

Calculated by Radon411

Dickinson County, Cities and towns

Cities and towns in Dickinson County

The Census Bureau estimates 18,077 residents in Dickinson County for July 1, 2025, 302 more than in 2020 (+1.7%). That works out to 48 people per square mile of land. Its largest town, Spirit Lake, has 5,525 residents, 30.6% of the total. Together its 10 incorporated places hold 73.7% of those residents; the other 26.3% live outside any of them. Testing is reported here more often than across the state: CDC's 831 reported tests for 2008 to 2017 come to 46.0 for every 1,000 residents (2025 estimate), against 29.4 for Iowa.

From Spirit Lake to Superior, CDC publishes no figure by town: each reads Dickinson County's.

The cities and towns in Dickinson County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Spirit Lake5,525+1.1%30.6%
Milford3,209−3.8%17.8%
Arnolds Park1,198+6.7%6.6%
Lake Park1,111−5.3%6.1%
Okoboji712−6.8%3.9%
Orleans493−5.4%2.7%
Wahpeton333−4.0%1.8%
West Okoboji309Level1.7%
Terril304−9.3%1.7%
Superior124−6.8%0.7%

10 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).

Dickinson County, Homes

Homes in Dickinson County

Of Dickinson County's 14,060 homes, 74% are detached houses, against 72% across Iowa; 13% are in buildings of five or more homes. Half of its homes were built before 1978, close to Iowa's 1971: 28% date from before 1960 and 27% from 2000 or later. Owners live in 77% of the occupied homes (Iowa: 72%), so for most households a test and a fix are their own to order.

Homes in Dickinson County, Iowa, 2019 to 2023
HomesDickinson CountyIowa
Housing units14,0601,427,175
Detached houses74%72%
In buildings of 5 or more13%14%
Mobile homes8%3%
Built before 196028%39%
Built since 200027%21%
Middle year built19781971
Owner-occupied77%72%

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