
Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
Locations and reports
EPA puts Wilson County in Zone 3, its lowest radon zone, and only 1 radon test from it is 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
Highest bordering
6.6%
Bexar County
1 of 5 neighbours have 30+ tests, 2007 to 2016
Nearest county
6.6%
Bexar County, 32 miles
Share at 4+ pCi/L, 197 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
Share of land USGS rates moderate or high potential
Tests reported
1
Too few for a share
2008 to 2017, laboratory
EPA radon zone
Zone 3
Lower potential
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Wilson 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
Wilson 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 1 reported test for Wilson County over the 2008 to 2017 laboratory totals, a result of 0.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Wilson County beside the counties around it is how this page reads it.
Only 1 test was reported to CDC for Wilson 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).
Wilson County, Compared
CDC's largest figure for Wilson County rests on 1 test over the 2008 to 2017 laboratory totals, 0 of them at or above 4 pCi/L, so each test moves its share by 100.0 points and no rank or comparison is drawn from it. Results reached as high as 0.1 pCi/L, with a middle value of 0.1 pCi/L.
Bexar County, the one bordering county with a figure over the 2007 to 2016 laboratory totals, reported 6.6% of its tests at or above 4 pCi/L. Farther out, Travis County (82 miles away) at 9.3%, Nueces County (104 miles away) at 0.0% and Williamson County (106 miles away) at 2.0% have figures too. Pooled across 140 Texas counties, 10.4% of reported tests reached that level; across every county in the country with a figure, 35.8%.
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 Wilson 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.
Wilson County, Geology
USGS's geologic map puts all of Wilson County's mapped land in one class: low radon potential. All of it lies in the area the map calls East Texas Province, to which USGS gives a radon index of 6, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| East Texas Province | Cretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite. | Low | 6 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Across Texas 0.5% of the land is rated high; none of Wilson County's is. None of the 5 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Wilson County, Local resources
The Texas Radon Group offers free radon test kits for Texas individuals who qualify.
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
Wilson County, Questions
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Wilson County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.1 pCi/L. Bexar County, the one bordering county with a figure over the 2007 to 2016 laboratory totals, reported 6.6% of its tests at or above 4 pCi/L.
Wilson County borders 5 counties: Karnes County, Bexar County, Atascosa County, Guadalupe County and Gonzales County.
Products
Wilson County, Products
No CDC figure names Wilson County; the nearest county with one, Bexar County (32 miles away), reported 6.6% 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 Wilson County.
Test kits and monitors: 1 of 3
Explore
Wilson County, Bordering counties
6.6%at or above 4 pCi/L
Median 0.6 pCi/L · 197 tests
0.0%at or above 4 pCi/L
Median 1.1 pCi/L · 1 test
0.0%at or above 4 pCi/L
Median 0.6 pCi/L · 3 tests
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 6 tests
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Wilson County, Cities and towns
Wilson County is growing: the Census Bureau puts it at 56,139 residents on July 1, 2025, up 12.2% from 50,051 in 2020. That works out to 70 people per square mile of land. No town dominates: Floresville, the largest, has 9,105 residents, 16.2% of the total. Reported testing is thin here: 1 test over 2008 to 2017, or under 0.1 for every 1,000 residents (2025 estimate), where Texas as a whole comes to 0.1.
From Floresville to Stockdale, CDC publishes no figure by town: each reads Wilson County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Floresville | 9,105 | +25.2% | 16.2% |
| Elmendorfextends beyond Wilson County | 3,111 | +66.6% | Counted whole |
| Nixonextends beyond Wilson County | 2,406 | +2.1% | Counted whole |
| Poth | 2,014 | +10.1% | 3.6% |
| La Vernia | 1,499 | +38.2% | 2.7% |
| Stockdale | 1,494 | +5.6% | 2.7% |
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). A place that extends beyond Wilson County is counted whole, so it has no share.
Wilson County, Homes
Of Wilson County's 19,259 homes, 69% are detached houses, against 65% across Texas; 25% are mobile homes. Much of Wilson County is recent building: 48% of its homes have gone up since 2000 and the middle year built is 1999, against 1990 for Texas. Owners live in 86% of the occupied homes (Texas: 63%), so for most households a test and a fix are their own to order.
| Homes | Wilson County | Texas |
|---|---|---|
| Housing units | 19,259 | 11,890,808 |
| Detached houses | 69% | 65% |
| In buildings of 5 or more | 2% | 21% |
| Mobile homes | 25% | 7% |
| Built before 1960 | 7% | 13% |
| Built since 2000 | 48% | 37% |
| Middle year built | 1999 | 1990 |
| Owner-occupied | 86% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.