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Radon Levels in Clinton County, Indiana

EPA puts Clinton County in Zone 1, its highest radon zone, and high results are common there: 45.9% of the 85 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

    45.9%

    7.0 pts above IN

    Clinton
    45.9%
    Indiana
    38.9%

    85 tests, 2008 to 2017

  • Median result

    3.5pCi/L

    Below action level

    Clinton
    3.5 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    85

    50th of 69 by tests

    Clinton
    85
    St. Joseph
    7,346

    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 Indiana

    28 of 69

    Middle half

    Clinton
    45.9%
    Miami
    63.3%

    By share, of 69 with 30+ tests

Read a result for Clinton County

Starts at Clinton County's median, 3.5 pCi/L

3.5pCi/L

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

EPA’s reading of 3.5 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Clinton County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Clinton County, At a glance

Clinton County at a glance

Predicted: EPA radon zone

EPA Zone 1: highest predicted potential

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

Reported results by concentration band, Clinton County, 2008 to 2017, laboratory
Under 2 pCi/L: 31%2 to 4 pCi/L: 23%4 pCi/L and above: 46%

Of 85 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Clinton County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L2630.6%
2 to 4 pCi/L2023.5%
4 pCi/L and above3945.9%
What these figures count

These are the 85 tests reported to CDC for Clinton 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

Clinton County, Compared

Clinton County radon figures, compared

Calculated by Radon411

In Clinton County, about 5 in 10 reported tests over the 2008 to 2017 laboratory totals (39 of 85) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 10.2 points higher. Across 92 Indiana counties pooled together, 38.9% of tests reached that level, so Clinton County runs 7.0 points above its state.

Of 7 neighbours with a figure, 3 reported a larger share at or above 4 pCi/L and 4 a smaller one; the spread is 36.8% (Tippecanoe County) to 60.5% (Carroll County). By share, Clinton County is 28th of 69 Indiana counties with 30 or more tests for the same period.

Half the tests came in under 3.5 pCi/L and half over it; the single highest reached 30.9 pCi/L. Below the action level, 26 tests (30.6%) came in under 2 pCi/L, against 32.8% statewide, and 20 tests (23.5%) fell between 2 and 4, against 28.3% statewide.

Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 45.9% share point the same way here. USGS geology rates 100% of the county's land high radon potential.

CDC's ten-year totals for Clinton County went from 65 tests (2005 to 2014) to 85 (2008 to 2017), the share going from 36.9% to 45.9%.

Clinton County against Indiana, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Clinton County
Clinton County8545.9%3.5 pCi/LThis county
Indiana, pooled92 counties, pooled43,14838.9%Not pooled−7.0 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−10.2 points
Miami Countyhighest in the state3063.3%5.3 pCi/L+17.4 points
Jasper Countylowest in the state7114.1%1.2 pCi/L−31.8 points
Carroll County, INborders it3860.5%5.8 pCi/L+14.6 points
Tipton County, INborders it6949.3%3.9 pCi/L+3.4 points
Howard County, INborders it21649.1%3.8 pCi/L+3.2 points
Montgomery County, INborders it15241.4%2.9 pCi/L−4.5 points
Boone County, INborders it61439.7%3.0 pCi/L−6.2 points
Hamilton County, INborders it3,47937.6%2.7 pCi/L−8.3 points
Tippecanoe County, INborders it1,21836.8%2.7 pCi/L−9.1 points
Where Clinton County's reported results fell, 2008 to 2017, laboratory, beside Indiana and the United States
ResultClinton County testsClinton County shareIndiana shareU.S. shareAgainst Indiana
Under 2 pCi/L2630.6%32.8%39.6%−2.2 points
2 to 4 pCi/L2023.5%28.3%24.7%−4.8 points
4 pCi/L and above3945.9%38.9%35.7%+7.0 points
Clinton County ranked among the 69 Indiana counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Wells County23 of 6916147.8%3.6 pCi/L
Clark County24 of 6951247.7%3.6 pCi/L
Porter County25 of 691,13646.5%3.5 pCi/L
Fulton County26 of 699746.4%3.3 pCi/L
Elkhart County27 of 692,85646.4%3.7 pCi/L
Clinton County28 of 698545.9%3.5 pCi/L
Jefferson County29 of 697245.8%3.1 pCi/L
Morgan County30 of 6922644.2%3.5 pCi/L
Dubois County31 of 6913644.1%3.7 pCi/L
Vigo County32 of 6945544.0%3.6 pCi/L
Huntington County33 of 6916943.8%3.5 pCi/L
Clinton County ten-year laboratory totals, against Indiana's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestIndiana, pooledChange from the row before
2008 to 20178545.9%3.5 pCi/L30.9 pCi/L38.9%+2.9 points
2007 to 20167943.0%3.3 pCi/L25.9 pCi/L39.2%+3.6 points
2006 to 20156639.4%3.0 pCi/L25.9 pCi/L39.6%+2.5 points
2005 to 20146536.9%2.9 pCi/L25.9 pCi/L39.3%First on file

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

Clinton County, Geology

The ground under Clinton County

Predicted

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

USGS's geologic areas under Clinton County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Huron-Erie LobeCalcareous clayey and loamy glacial deposits derived from marine carbonate and clastic sedimentary rocks.High13100%

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

Clinton County beside the ground around it

Clinton County has more high-potential ground than Indiana as a whole: 100% of its land against 56.6%. Of the 7 counties that border it, none has as large a share of high-potential ground; Boone County comes nearest at 100%.

Share of land by USGS radon potential: Clinton County, the 7 counties bordering it and Indiana
AreaEPA zoneLow potentialModerate potentialHigh potential
Clinton CountyZone 1NoneNone100%
Boone CountyZone 1NoneNone100%
Tipton CountyZone 1NoneNone100%
Carroll CountyZone 1NoneNone100%
Howard CountyZone 1NoneNone100%
Tippecanoe CountyZone 1NoneNone100%
Hamilton CountyZone 1NoneNone100%
Montgomery CountyZone 1None5.9%94.1%
Indiana92 counties, pooled by land areaVariesNone43.4%56.6%

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

Local help

Clinton County, Local resources

Radon testing and mitigation in Clinton County

What Indiana's program says
Phone
1-800-272-9723
Licensing of radon professionals
According to the Indiana Radon Rule, 410 IAC 5.1, everyone who is serving Indiana by doing radon testing, analysis and mitigation (radon reduction) in residential structures must be certified by the Indiana State Department of Health.

What it means

Clinton County, Questions

Questions about radon in Clinton County

Are radon levels high in Clinton County?

Over the 2008 to 2017 laboratory totals, 45.9% of the radon tests reported to CDC for Clinton County, Indiana were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.5 pCi/L. Of 69 Indiana counties with 30 or more tests for the same period, 27 reported a higher share; pooled, the state comes to 38.9%.

Which counties border Clinton County?

Clinton County borders 7 counties: Boone County, Tipton County, Carroll County, Howard County, Tippecanoe County, Hamilton County and Montgomery County.

Products

Clinton County, Products

Testing a home in Clinton County

In Clinton County, 45.9% of 85 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 38.9% pooled across Indiana. In Zone 1 the year-round level in Clinton 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

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

Explore

Clinton County, Bordering counties

Counties bordering Clinton County

Calculated by Radon411

Clinton County, Cities and towns

Cities and towns in Clinton County

Clinton County's population has barely moved since 2020: 33,322 residents on July 1, 2025 against 33,185 then, by the Census Bureau's estimates. That works out to 82 people per square mile of land. Frankfort alone is home to 16,837 of them, 50.5% of the total. Together its 6 incorporated places hold 64.4% of those residents; the other 35.6% live outside any of them. Reported testing is thin here: 85 tests over 2008 to 2017, or 2.6 for every 1,000 residents (2025 estimate), where Indiana as a whole comes to 6.2.

From Frankfort to Michigantown, CDC publishes no figure by town: each reads Clinton County's.

The cities and towns in Clinton County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Frankfort16,837−0.2%50.5%
Rossville1,525+1.5%4.6%
Mulberry1,224−0.6%3.7%
Kirklin717+1.0%2.2%
Colfax714+1.0%2.1%
Michigantown430−1.4%1.3%

6 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).

Clinton County, Homes

Homes in Clinton County

Clinton County is a place of houses on their own lots: 84% of its 13,496 homes are detached single-family houses, against 73% across Indiana. The homes are older than Indiana's as a whole: half were built before 1958 (1976 for Indiana), and 52% date from before 1960. 74% of occupied homes are lived in by their owner (Indiana: 70%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Clinton County, Indiana, 2019 to 2023
HomesClinton CountyIndiana
Housing units13,4962,953,344
Detached houses84%73%
In buildings of 5 or more7%13%
Mobile homes3%4%
Built before 196052%32%
Built since 20008%21%
Middle year built19581976
Owner-occupied74%70%

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