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Radon Levels in Montgomery County, Kentucky

EPA puts Montgomery County in Zone 2, its middle radon zone, and high results are common there: 51.4% of the 105 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

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  • Share at 4+ pCi/L

    51.4%

    7.7 pts above KY

    Montgomery
    51.4%
    Kentucky
    43.7%

    105 tests, 2008 to 2017

  • Median result

    4.1pCi/L

    Action level reached

    Montgomery
    4.1 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    105

    34th of 69 by tests

    Montgomery
    105
    Jefferson
    6,590

    Reported to CDC before any fix, 2008 to 2017

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Kentucky

    15 of 69

    Top quarter

    Montgomery
    51.4%
    Meade
    68.4%

    By share, of 69 with 30+ tests

Read a result for Montgomery County

Starts at Montgomery County's median, 4.1 pCi/L

4.1pCi/L

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

EPA’s reading of 4.1 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. Montgomery County's median reported result, 2008 to 2017.

Interpret this readingWhat a fix costs

The data

Montgomery County, At a glance

Montgomery County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Montgomery County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 61% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Montgomery County, 2008 to 2017, laboratory

Reported results by concentration band, Montgomery County, 2008 to 2017, laboratory
Under 2 pCi/L: 25%2 to 4 pCi/L: 24%4 pCi/L and above: 51%

Of 105 pre-mitigation tests reported to CDC, not homes in this area.

Reported results by concentration band, Montgomery County, 2008 to 2017, laboratory: data table
Result bandTests MeasuredShare Measured
Under 2 pCi/L2624.8%
2 to 4 pCi/L2523.8%
4 pCi/L and above5451.4%
What these figures count

These are the 105 tests reported to CDC for Montgomery 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

Montgomery County, Compared

Montgomery County radon figures, compared

Calculated by Radon411

More than half: 51.4% of the 105 radon tests reported to CDC for Montgomery County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 15th of 69 Kentucky counties with 30 or more tests for the same period. That is 7.7 points above the 43.7% pooled from 120 Kentucky counties.

The median result, 4.1 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 24.0 pCi/L. The rest split 24.8% under 2 pCi/L and 23.8% from 2 to 4 (Kentucky: 33.2% and 23.1%). The reported tests do not follow EPA's Zone 2 label for Montgomery County (predicted average between 2 and 4 pCi/L): 51.4% of them reached 4 pCi/L, fewer than that label suggests.

1 of its 3 bordering counties with figures ran higher, led by Bourbon County at 53.5%; Menifee County reported 22.0%. Statewide for the same period, Meade County reported the highest share (68.4%) and Hopkins County the lowest (9.5%).

CDC's ten-year totals for Montgomery County went from 97 tests (2005 to 2014) to 105 (2008 to 2017), the share going from 55.7% to 51.4%.

Nationally, every county with a figure for the same period pools to 35.7%; Montgomery County sits 15.7 points above it. CDC also counts 8 tests taken after mitigation in Montgomery County for the same period: tests in homes where a fix was already in.

Montgomery County against Kentucky, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Montgomery County
Montgomery County10551.4%4.1 pCi/LThis county
Kentucky, pooled120 counties, pooled28,79343.7%Not pooled−7.7 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled−15.7 points
Meade Countyhighest in the state11768.4%8.2 pCi/L+17.0 points
Hopkins Countylowest in the state429.5%1.7 pCi/L−41.9 points
Bourbon County, KYborders it12753.5%4.8 pCi/L+2.1 points
Powell County, KYborders it2944.8%3.2 pCi/L−6.6 points
Bath County, KYborders it1241.7%3.1 pCi/L−9.7 points
Clark County, KYborders it23129.0%2.4 pCi/L−22.4 points
Menifee County, KYborders it4122.0%1.4 pCi/L−29.4 points
Nicholas County, KYborders it2010.0%1.9 pCi/L−41.4 points
Where Montgomery County's reported results fell, 2008 to 2017, laboratory, beside Kentucky and the United States
ResultMontgomery County testsMontgomery County shareKentucky shareU.S. shareAgainst Kentucky
Under 2 pCi/L2624.8%33.2%39.6%−8.4 points
2 to 4 pCi/L2523.8%23.1%24.7%+0.7 points
4 pCi/L and above5451.4%43.7%35.7%+7.7 points
Montgomery County ranked among the 69 Kentucky counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Fayette County10 of 695,26354.5%4.5 pCi/L
Boyle County11 of 6949253.9%4.4 pCi/L
Bourbon County12 of 6912753.5%4.8 pCi/L
Monroe County13 of 698752.9%4.6 pCi/L
Barren County14 of 6918651.6%4.0 pCi/L
Montgomery County15 of 6910551.4%4.1 pCi/L
Hardin County16 of 6942950.3%4.0 pCi/L
Marion County17 of 6917748.6%3.9 pCi/L
Bullitt County18 of 6955147.5%3.6 pCi/L
Clinton County19 of 694047.5%3.5 pCi/L
Larue County20 of 693447.1%3.7 pCi/L
Montgomery County ten-year laboratory totals, against Kentucky's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestKentucky, pooledChange from the row before
2008 to 201710551.4%4.1 pCi/L24.0 pCi/L43.7%−2.1 points
2007 to 20169953.5%4.4 pCi/L24.0 pCi/L45.1%−0.7 points
2006 to 201510754.2%4.4 pCi/L24.0 pCi/L46.4%−1.5 points
2005 to 20149755.7%4.8 pCi/L24.0 pCi/L47.3%First on file

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

Montgomery County, Geology

The ground under Montgomery County

Predicted

USGS's geologic map splits Montgomery County: 61.3% of its land is moderate radon potential and 38.7% high. The map puts 48.8% of Montgomery County in the area it calls Outer Bluegrass and 38.7% in New Albany-Chattanooga Shale, with 2 smaller areas beside them. USGS gives the first a radon index of 11, in the moderate band (9 to 11), and the second 14, in the high band (12 to 17).

USGS's geologic areas under Montgomery County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Outer BluegrassOrdovician-Devonian limestone and shale.Moderate1148.8%
New Albany-Chattanooga ShaleDevonian/Mississippian Black shale.High1438.7%
Mississippian PlateauMississippian marine limestones, dolomites, marine sandstones, siltstones, and shales.Moderate1110.1%
Cumberland PlateauPennsylvanian sandstones, siltstones, and shales.Moderate92.4%

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

Montgomery County beside the ground around it

Montgomery County has more high-potential ground than Kentucky as a whole: 38.7% of its land against 18.2%. Of the 6 counties that border it, 1 has more high-potential ground, Bourbon County the most at 44.1%.

Share of land by USGS radon potential: Montgomery County, the 6 counties bordering it and Kentucky
AreaEPA zoneLow potentialModerate potentialHigh potential
Montgomery CountyZone 2None61.3%38.7%
Bath CountyZone 2None64.6%35.4%
Clark CountyZone 1None73.0%27.0%
Powell CountyZone 2None75.6%24.4%
Nicholas CountyZone 2None97.3%2.7%
Menifee CountyZone 2None100%None
Bourbon CountyZone 1None55.9%44.1%
Kentucky120 counties, pooled by land areaVaries5.7%76.1%18.2%

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

Local help

Montgomery County, Local resources

Radon testing and mitigation in Montgomery County

What Kentucky's program says
Phone
502-782-2782
Email
Radon@ky.gov

What it means

Montgomery County, Questions

Questions about radon in Montgomery County

Are radon levels high in Montgomery County?

Over the 2008 to 2017 laboratory totals, 51.4% of the radon tests reported to CDC for Montgomery County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 4.1 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 14 reported a higher share; pooled, the state comes to 43.7%.

Which counties border Montgomery County?

Montgomery County borders 6 counties: Bath County, Clark County, Powell County, Nicholas County, Menifee County and Bourbon County.

Products

Montgomery County, Products

Testing a home in Montgomery County

In Montgomery County, 51.4% of 105 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.7% pooled across Kentucky. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Montgomery County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Montgomery County homes, compared

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Montgomery County, Bordering counties

Counties bordering Montgomery County

Calculated by Radon411

Montgomery County, Cities and towns

Cities and towns in Montgomery County

The Census Bureau estimates 28,822 residents in Montgomery County for July 1, 2025, 707 more than in 2020 (+2.5%). That works out to 146 people per square mile of land. Its largest town, Mount Sterling, has 7,586 residents, 26.3% of the total. Together its 3 incorporated places hold 37.4% of those residents; the other 62.6% live outside any of them. Reported testing is thin here: 105 tests over 2008 to 2017, or 3.6 for every 1,000 residents (2025 estimate), where Kentucky as a whole comes to 6.3.

From Mount Sterling to Camargo, CDC publishes no figure by town: each reads Montgomery County's.

The cities and towns in Montgomery County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Mount Sterling7,586+0.6%26.3%
Jeffersonville2,137+3.8%7.4%
Camargo1,051+2.9%3.6%

3 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).

Montgomery County, Homes

Homes in Montgomery County

Of Montgomery County's 12,204 homes, 65% are detached houses, against 68% across Kentucky; 16% are mobile homes. Half of its homes were built before 1985, close to Kentucky's 1982: 18% date from before 1960 and 30% from 2000 or later. 66% of occupied homes are lived in by their owner (Kentucky: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Montgomery County, Kentucky, 2019 to 2023
HomesMontgomery CountyKentucky
Housing units12,2042,010,655
Detached houses65%68%
In buildings of 5 or more5%12%
Mobile homes16%11%
Built before 196018%22%
Built since 200030%24%
Middle year built19851982
Owner-occupied66%68%

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