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
Radon Levels in Clay County, Texas
EPA puts Clay County in Zone 3, its lowest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
7.2%
Denton County, 75 miles
- Denton
- 7.2%
- Texas
- 10.4%
Share at 4+ pCi/L, 181 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Clay
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
0
None published
A home here needs its own test
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Clay County
Starts at EPA's action level
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
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 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
Clay County, At a glance
Clay County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
No CDC test figures here
CDC has published no radon test figures for Clay County. Denton County, 75 miles away, is the nearest county with a figure over the 2007 to 2016 laboratory totals.
Clay County, Compared
Clay County radon figures, compared
Calculated by Radon411No CDC figure names Clay County, in any year or ten-year total; over the 2007 to 2016 laboratory totals, the agency's counts reach 140 Texas counties without it. Pooled across 140 Texas counties, 10.4% of reported tests reached that level; across every county in the country with a figure, 35.8%.
The nearest counties with a figure are Denton County (75 miles away) at 7.2%, Tarrant County (88 miles away) at 10.6% and Collin County (103 miles away) at 7.7%. Statewide for the same period, Randall County reported the highest share (71.4%) and Nueces County the lowest (0.0%).
EPA's 1993 map puts Clay 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.
Clay County, Geology
The ground under Clay County
PredictedUSGS's geologic map puts all of Clay County's mapped land in one class: low radon potential. All of it lies in the area the map calls Central Texas, 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 Texas | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 7 | 99.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Clay County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Clay County's is. None of the 6 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Clay County, Local resources
Radon testing and mitigation in Clay County
- Texas Radon GroupTexas Radon Group, run by Texas Tech University, does not license radon professionals and offers free or discounted test kits, and answers questions about testing and mitigation in Texas.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Texas Radon Group offers free radon test kits for Texas individuals who qualify.
- Compare kits
- Professionals in Texas7 professionals are listed in Texas.
What Texas's program says
- Licensing of radon professionals
There are no radon certification requirements for the State of Texas at this time, but the National Radon Proficiency Program lists radon testers and mitigators within Texas that have passed a rigorous national certification program.
What it means
Clay County, Questions
Questions about radon in Clay County
Are radon levels high in Clay County?
No CDC testing statistics are published here for Clay County, Texas yet. Of the 8 nearest counties with a figure, within 208 miles, the share of tests at or above 4 pCi/L runs from 7.2% to 57.8%.
Which counties border Clay County?
Clay County borders 6 counties: Montague County, TX, Archer County, TX, Jack County, TX, Jefferson County, OK, Wichita County, TX and Cotton County, OK.
Products
Clay County, Products
Testing a home in Clay County
No CDC figure names Clay County; the nearest county with one, Denton County (75 miles away), reported 7.2% of its tests at or above 4 pCi/L over the 2007 to 2016 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 Clay County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorAranet
Radon One battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Clay County, Bordering counties
Counties bordering Clay County
Calculated by Radon411- Radon levels in Montague County, TXEPA zone 3
12.5%at or above 4 pCi/L
Median 0.1 pCi/L · 16 tests
- Radon levels in Jefferson County, OKEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
- Radon levels in Wichita County, TXEPA zone 3
0.0%at or above 4 pCi/L
Median 0.7 pCi/L · 9 tests
- Radon levels in Archer County, TXEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in Jack County, TXEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in Cotton County, OKEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Clay County, Cities and towns
Cities and towns in Clay County
The Census Bureau estimates 10,764 residents in Clay County for July 1, 2025, 509 more than in 2020 (+5.0%). Spread over its land, that is 9.9 people to the square mile. Its largest town, Henrietta, has 3,258 residents, 30.3% of the total. CDC publishes no radon test count for Clay County; across Texas its counts for 2007 to 2016 come to 0.1 tests for every 1,000 residents (2025 estimate).
From Henrietta to Jolly, CDC publishes no figure by town: each reads Clay County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Henrietta | 3,258 | +5.0% | 30.3% |
| Petrolia | 534 | +4.5% | 5.0% |
| Dean | 521 | +5.7% | 4.8% |
| Byers | 469 | +5.2% | 4.4% |
| Windthorstextends beyond Clay County | 354 | +2.9% | Counted whole |
| Bellevue | 298 | +4.9% | 2.8% |
| Jolly | 168 | +3.7% | 1.6% |
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 Clay County is counted whole, so it has no share.
Clay County, Homes
Homes in Clay County
Clay County is a place of houses on their own lots: 82% of its 5,154 homes are detached single-family houses, against 65% across Texas. The homes are older than Texas' as a whole: half were built before 1977 (1990 for Texas), and 27% date from before 1960. Owners live in 81% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.
| Homes | Clay County | Texas |
|---|---|---|
| Housing units | 5,154 | 11,890,808 |
| Detached houses | 82% | 65% |
| In buildings of 5 or more | under 1% | 21% |
| Mobile homes | 15% | 7% |
| Built before 1960 | 27% | 13% |
| Built since 2000 | 22% | 37% |
| Middle year built | 1977 | 1990 |
| Owner-occupied | 81% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.