
Short-term kit![]()
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
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
Share at 4+ pCi/L, 135 tests, 2006 to 2015
Ground above low
None
15.2 pts below Oklahoma
Share of land USGS rates moderate or high potential
Tests reported
3
Too few for a share
2005 to 2014, laboratory
EPA radon zone
Zone 3
Lower potential
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Custer County
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
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
Predicted: EPA radon zone
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
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.
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).
Custer County, Compared
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.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Custer County, Geology
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).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Central Oklahoma Plains and Hills | Nonmarine Permian and Tertiary rocks, including shale, sandstone, and conglomerate in the western part, and Mississippian and Pennsylvanian rocks in the eastern part. | Low | 7 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
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%.
The map rates the ground, not the air in any home.
Local help
Custer County, Local resources
What it means
Custer County, Questions
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%.
Custer County borders 6 counties: Dewey County, Washita County, Blaine County, Roger Mills County, Beckham County and Caddo County.
Products
Custer County, Products
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 monitors: 1 of 3
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Custer County, Bordering counties
33.3%at or above 4 pCi/L
Median 3.3 pCi/L · 6 tests
0.0%at or above 4 pCi/L
Median 2.8 pCi/L · 3 tests
0.0%at or above 4 pCi/L
Median 3.2 pCi/L · 1 test
0.0%at or above 4 pCi/L
Median 1.5 pCi/L · 5 tests
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
Custer County, Cities and towns
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.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Weatherford | 12,005 | −0.3% | 42.6% |
| Clintonextends beyond Custer County | 8,302 | −2.3% | Counted whole |
| Thomas | 1,129 | −1.7% | 4.0% |
| Arapaho | 660 | Level | 2.3% |
| Hammonextends beyond Custer County | 455 | −4.0% | Counted whole |
| Custer City | 371 | +0.3% | 1.3% |
| Butler | 207 | Level | 0.7% |
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
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 | Custer County | Oklahoma |
|---|---|---|
| Housing units | 12,946 | 1,763,036 |
| Detached houses | 70% | 73% |
| In buildings of 5 or more | 14% | 12% |
| Mobile homes | 10% | 9% |
| Built before 1960 | 22% | 21% |
| Built since 2000 | 21% | 25% |
| Middle year built | 1977 | 1980 |
| Owner-occupied | 64% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.