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Radon Levels in Ida County, Iowa

EPA puts Ida County in Zone 1, its highest radon zone, and high results are common there: 71.7% of the 399 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

    71.7%

    13.2 pts above IA

    Ida
    71.7%
    Iowa
    58.5%

    399 tests, 2008 to 2017

  • Median result

    7.4pCi/L

    Action level reached

    Ida
    7.4 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    399

    59th of 99 by tests

    Ida
    399
    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

    20 of 99

    Top quarter

    Ida
    71.7%
    Sioux
    84.2%

    By share, of 99 with 30+ tests

Read a result for Ida County

Starts at Ida County's median, 7.4 pCi/L

7.4pCi/L

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

EPA’s reading of 7.4 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. Ida County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Ida County, At a glance

Ida County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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

Reported results by concentration band, Ida County, 2008 to 2017, laboratory
Under 2 pCi/L: 14%2 to 4 pCi/L: 14%4 pCi/L and above: 72%

Of 399 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Ida County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L5814.5%
2 to 4 pCi/L5513.8%
4 pCi/L and above28671.7%
What these figures count

These are the 399 tests reported to CDC for Ida 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

Ida County, Compared

Ida County radon figures, compared

Calculated by Radon411

More than half: 71.7% of the 399 radon tests reported to CDC for Ida County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 20th of 99 Iowa counties with 30 or more tests for the same period. That is 13.2 points above the 58.5% pooled from 99 Iowa counties.

The median result, 7.4 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 78.0 pCi/L. The rest split 14.5% under 2 pCi/L and 13.8% from 2 to 4 (Iowa: 21.8% and 19.7%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 71.7% share point the same way here.

5 of its 6 bordering counties with figures ran higher, led by Sac County at 76.6%; Woodbury County reported 69.2%. 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 Ida County went from 264 tests (2005 to 2014) to 399 (2008 to 2017), the share going from 74.2% to 71.7%.

Nationally, every county with a figure for the same period pools to 35.7%; Ida County sits 36.0 points above it. CDC also counts 9 tests taken after mitigation in Ida County for the same period: tests in homes where a fix was already in.

Ida County against Iowa, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Ida County
Ida County39971.7%7.4 pCi/LThis county
Iowa, pooled99 counties, pooled95,24558.5%Not pooled−13.2 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−36.0 points
Sioux Countyhighest in the state1,98284.2%10.7 pCi/L+12.5 points
Decatur Countylowest in the state8525.9%2.5 pCi/L−45.8 points
Sac County, IAborders it49176.6%7.0 pCi/L+4.9 points
Crawford County, IAborders it37374.8%7.0 pCi/L+3.1 points
Monona County, IAborders it60374.6%7.0 pCi/L+2.9 points
Cherokee County, IAborders it79574.5%7.6 pCi/L+2.8 points
Buena Vista County, IAborders it68872.1%6.9 pCi/L+0.4 points
Woodbury County, IAborders it3,54169.2%6.1 pCi/L−2.5 points
Where Ida County's reported results fell, 2008 to 2017, laboratory, beside Iowa and the United States
ResultIda County testsIda County shareIowa shareU.S. shareAgainst Iowa
Under 2 pCi/L5814.5%21.8%39.6%−7.3 points
2 to 4 pCi/L5513.8%19.7%24.7%−5.9 points
4 pCi/L and above28671.7%58.5%35.7%+13.2 points
Ida 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
Jasper County15 of 9974673.3%8.2 pCi/L
Allamakee County16 of 9949273.2%7.0 pCi/L
Adair County17 of 999872.4%9.3 pCi/L
Buena Vista County18 of 9968872.1%6.9 pCi/L
Winnebago County19 of 9982971.9%6.7 pCi/L
Ida County20 of 9939971.7%7.4 pCi/L
Page County21 of 9965371.7%7.2 pCi/L
Greene County22 of 9914371.3%6.2 pCi/L
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
Ida County ten-year laboratory totals, against Iowa's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIowa, pooledChange from the row before
2008 to 201739971.7%7.4 pCi/L78.0 pCi/L58.5%−0.2 points
2007 to 201638571.9%7.6 pCi/L63.0 pCi/L58.6%−1.7 points
2006 to 201531173.6%8.1 pCi/L63.0 pCi/L59.4%−0.6 points
2005 to 201426474.2%8.0 pCi/L63.0 pCi/L59.6%First on file

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

Ida County, Geology

The ground under Ida County

Predicted

USGS's geologic map puts all of Ida County's mapped land in one class: high radon potential. All of it lies in the area the map calls Loess-Covered Drift Plains, to which USGS gives a radon index of 13, in the high band (12 to 17).

USGS's geologic areas under Ida County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Loess-Covered Drift PlainsPre-Illinoian and Illinoian glacial deposits, and loess.High13100%

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

Ida County beside the ground around it

On high-potential ground Ida 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; Cherokee County comes nearest at 100%.

Share of land by USGS radon potential: Ida County, the 6 counties bordering it and Iowa
AreaEPA zoneLow potentialModerate potentialHigh potential
Ida CountyZone 1NoneNone100%
Sac CountyZone 1NoneNone100%
Crawford CountyZone 1NoneNone100%
Cherokee CountyZone 1NoneNone100%
Woodbury CountyZone 1NoneNone100%
Monona CountyZone 1NoneNone100%
Buena Vista CountyZone 1NoneNone100%
Iowa99 counties, pooled by land areaVariesNone1.2%98.8%

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

Local help

Ida County, Local resources

Radon testing and mitigation in Ida County

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

Ida County, Questions

Questions about radon in Ida County

Are radon levels high in Ida County?

Over the 2008 to 2017 laboratory totals, 71.7% of the radon tests reported to CDC for Ida County, Iowa were at or above 4 pCi/L, and the median reported pre-mitigation result was 7.4 pCi/L. Of 99 Iowa counties with 30 or more tests for the same period, 19 reported a higher share; pooled, the state comes to 58.5%.

Which counties border Ida County?

Ida County borders 6 counties: Sac County, Crawford County, Cherokee County, Woodbury County, Monona County and Buena Vista County.

Products

Ida County, Products

Testing a home in Ida County

In Ida County, 71.7% of 399 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 Ida 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

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

Explore

Ida County, Bordering counties

Counties bordering Ida County

Calculated by Radon411

Ida County, Cities and towns

Cities and towns in Ida County

About 6,777 people live in Ida County by the Census Bureau's estimate for July 1, 2025, 242 fewer than in 2020 (−3.4%). That works out to 16 people per square mile of land. Its largest town, Ida Grove, has 1,986 residents, 29.3% of the total. Together its 5 incorporated places hold 70.3% of those residents; the other 29.7% live outside any of them. Testing is reported here more often than across the state: CDC's 399 reported tests for 2008 to 2017 come to 58.9 for every 1,000 residents (2025 estimate), against 29.4 for Iowa.

From Ida Grove to Arthur, CDC publishes no figure by town: each reads Ida County's.

The cities and towns in Ida County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Ida Grove1,986−4.0%29.3%
Holstein1,470−2.8%21.7%
Battle Creek678−3.0%10.0%
Galva415−4.8%6.1%
Arthur215−3.2%3.2%

5 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).

Ida County, Homes

Homes in Ida County

Ida County is a place of houses on their own lots: 86% of its 3,365 homes are detached single-family houses, against 72% across Iowa. The homes are older than Iowa's as a whole: half were built before 1952 (1971 for Iowa), and 60% date from before 1960. Owners live in 78% of the occupied homes (Iowa: 72%), so for most households a test and a fix are their own to order.

Homes in Ida County, Iowa, 2019 to 2023
HomesIda CountyIowa
Housing units3,3651,427,175
Detached houses86%72%
In buildings of 5 or more6%14%
Mobile homes1%3%
Built before 196060%39%
Built since 20009%21%
Middle year built19521971
Owner-occupied78%72%

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