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Radon Levels in Custer County, Oklahoma

EPA puts Custer County in Zone 3, its lowest radon zone, and only 2 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

  • Nearest county

    8.9%

    Oklahoma County, 90 miles

    Oklahoma
    8.9%
    Oklahoma
    12.6%

    Share at 4+ pCi/L, 135 tests, 2006 to 2015

  • Ground above low

    None

    15.2 pts below Oklahoma

    Custer
    0.0%
    Oklahoma
    15.2%

    Share of land USGS rates moderate or high potential

  • Tests reported

    3

    Too few for a share

    Custer
    3
    Needed
    30

    2005 to 2014, laboratory

  • EPA radon zone

    Zone 3

    Lower potential

    1. 1
    2. 2
    3. Zone 3

    1 highest, 3 lowest

    EPA predicts under 2 pCi/L indoors

Read a result for Custer County

Starts at EPA's action level

4.0pCi/L

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

EPA’s reading of 4.0 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.

The data

Custer County, At a glance

Custer County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Custer County as a whole is an average indoor of less than 2 pCi/L (less than 75 Bq/m³). A low zone clears no address in it: homes above EPA's turn up in all three zones.

USGS geologic potential: Low across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

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

CDC holds 2 reported tests for Custer County over the 2008 to 2017 laboratory totals, with a median of 2.3 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Custer County beside the counties around it is how this page reads it.

What these figures count

Only 2 tests were reported to CDC for Custer County over 2008 to 2017 (laboratory totals), and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor 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

Custer County, Compared

Custer County radon figures, compared

Calculated by Radon411

CDC's largest figure for Custer County rests on 3 tests over the 2005 to 2014 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 33.3 points and no rank or comparison is drawn from it. Results reached as high as 2.4 pCi/L, with a middle value of 2.2 pCi/L.

The nearest counties with a figure are Oklahoma County (90 miles away) at 8.9%, Tulsa County (175 miles away) at 6.0% and Washington County (188 miles away) at 11.3%. Pooled across 53 Oklahoma counties, 12.6% of reported tests reached that level; across every county in the country with a figure, 36.3%.

Statewide for the same period, Delaware County reported the highest share (44.7%) and Tulsa County the lowest (6.0%). EPA's 1993 map puts Custer County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 100% of the county's land low radon potential.

Oklahoma, the United States and the counties around Custer County, 2006 to 2015, laboratory
AreaTestsAt or above 4 pCi/LMedian
Oklahoma, pooled53 counties, pooled86012.6%Not pooled
United States, pooled2,669 counties, pooled1,805,52836.3%Not pooled
Delaware Countyhighest in the state3844.7%2.5 pCi/L
Tulsa Countylowest in the state3006.0%0.9 pCi/L
Dewey County, OKborders it633.3%3.3 pCi/L
Beckham County, OKborders it50.0%1.5 pCi/L
Roger Mills County, OKborders it10.0%3.2 pCi/L
Washita County, OKborders it30.0%2.8 pCi/L
The nearest Oklahoma counties to Custer County with 30 or more tests, 2006 to 2015, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Oklahoma County90 mi1358.9%0.9 pCi/L
Tulsa County175 mi3006.0%0.9 pCi/L
Washington County188 mi5311.3%1.9 pCi/L
Cherokee County226 mi5032.0%1.9 pCi/L
Delaware County241 mi3844.7%2.5 pCi/L
Custer County ten-year laboratory totals, against Oklahoma's pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestOklahoma, pooledChange from the row before
2008 to 201720.0%2.3 pCi/L2.4 pCi/L12.7%Level
2007 to 201620.0%2.3 pCi/L2.4 pCi/L12.1%Level
2006 to 201520.0%2.3 pCi/L2.4 pCi/L12.6%Level
2005 to 201430.0%2.2 pCi/L2.4 pCi/L12.0%First on file

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

Custer County, Geology

The ground under Custer County

Predicted

USGS's geologic map puts all of Custer County's mapped land in one class: low radon potential. All of it lies in the area the map calls Central Oklahoma Plains and Hills, to which USGS gives a radon index of 7, in the low band (5 to 8).

USGS's geologic areas under Custer County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Central Oklahoma Plains and HillsNonmarine Permian and Tertiary rocks, including shale, sandstone, and conglomerate in the western part, and Mississippian and Pennsylvanian rocks in the eastern part.Low7100%

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

Custer County beside the ground around it

Across Oklahoma 0.6% of the land is rated high; none of Custer County's is. Of the 6 counties that border it, 3 have more moderate-potential ground, Roger Mills County the most at 34.2%.

Share of land by USGS radon potential: Custer County, the 6 counties bordering it and Oklahoma
AreaEPA zoneLow potentialModerate potentialHigh potential
Custer CountyZone 3100%NoneNone
Dewey CountyZone 397.8%2.2%None
Washita CountyZone 3100%NoneNone
Blaine CountyZone 3100%NoneNone
Roger Mills CountyZone 365.8%34.2%None
Beckham CountyZone 399.9%0.1%None
Caddo CountyZone 3100%NoneNone
Oklahoma77 counties, pooled by land areaVaries84.8%14.6%0.6%

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

What it means

Custer County, Questions

Questions about radon in Custer County

Are radon levels high in Custer County?

Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Custer County, Oklahoma were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.3 pCi/L. Of the 5 nearest counties with a figure, within 241 miles, the share of tests at or above 4 pCi/L runs from 6.0% to 44.7%.

Which counties border Custer County?

Custer County borders 6 counties: Dewey County, Washita County, Blaine County, Roger Mills County, Beckham County and Caddo County.

Products

Custer County, Products

Testing a home in Custer County

No CDC figure names Custer County; the nearest county with one, Oklahoma County (90 miles away), reported 8.9% of its tests at or above 4 pCi/L over the 2006 to 2015 laboratory totals, the only reading nearby until a test of this home. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Custer County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Custer County homes, compared

Explore

Custer County, Bordering counties

Counties bordering Custer County

Calculated by Radon411

Custer County, Cities and towns

Cities and towns in Custer County

About 28,175 people live in Custer County by the Census Bureau's estimate for July 1, 2025, 273 fewer than in 2020 (−1.0%). That works out to 28 people per square mile of land. Its largest town, Weatherford, has 12,005 residents, 42.6% of the total. Reported testing is thin here: 3 tests over 2005 to 2014, or 0.1 for every 1,000 residents (2025 estimate), where Oklahoma as a whole comes to 0.2.

From Weatherford to Butler, CDC publishes no figure by town: each reads Custer County's.

The cities and towns in Custer County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Weatherford12,005−0.3%42.6%
Clintonextends beyond Custer County8,302−2.3%Counted whole
Thomas1,129−1.7%4.0%
Arapaho660Level2.3%
Hammonextends beyond Custer County455−4.0%Counted whole
Custer City371+0.3%1.3%
Butler207Level0.7%

7 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). A place that extends beyond Custer County is counted whole, so it has no share.

Custer County, Homes

Homes in Custer County

Of Custer County's 12,946 homes, 70% are detached houses, against 73% across Oklahoma; 14% are in buildings of five or more homes. Half of its homes were built before 1977, close to Oklahoma's 1980: 22% date from before 1960 and 21% from 2000 or later. 64% of occupied homes are lived in by their owner (Oklahoma: 66%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Custer County, Oklahoma, 2019 to 2023
HomesCuster CountyOklahoma
Housing units12,9461,763,036
Detached houses70%73%
In buildings of 5 or more14%12%
Mobile homes10%9%
Built before 196022%21%
Built since 200021%25%
Middle year built19771980
Owner-occupied64%66%

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