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Radon Levels in Wilson County, Texas

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

    Bexar
    6.6%

    1 of 5 neighbours have 30+ tests, 2007 to 2016

  • Nearest county

    6.6%

    Bexar County, 32 miles

    Bexar
    6.6%
    Texas
    10.4%

    Share at 4+ pCi/L, 197 tests, 2007 to 2016

  • Ground above low

    None

    27.3 pts below Texas

    Wilson
    0.0%
    Texas
    27.3%

    Share of land USGS rates moderate or high potential

  • Tests reported

    1

    Too few for a share

    Wilson
    1
    Needed
    30

    2008 to 2017, 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 Wilson 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

Wilson County, At a glance

Wilson County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

is EPA's lowest class, and its forecast for Wilson 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 Wilson County, 2008 to 2017, laboratory

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.

What these figures count

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).

How to read these figures

Wilson County, Compared

Wilson County radon figures, compared

Calculated by Radon411

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.

Texas, the United States and the counties around Wilson County, 2007 to 2016, laboratory
AreaTestsAt or above 4 pCi/LMedian
Texas, pooled140 counties, pooled4,54810.4%Not pooled
United States, pooled2,666 counties, pooled1,939,02535.8%Not pooled
Randall Countyhighest in the state8471.4%6.2 pCi/L
Nueces Countylowest in the state450.0%0.6 pCi/L
Bexar County, TXborders it1976.6%0.6 pCi/L
Atascosa County, TXborders it10.0%1.1 pCi/L
Gonzales County, TXborders it60.0%0.1 pCi/L
Guadalupe County, TXborders it30.0%0.6 pCi/L
The nearest Texas counties to Wilson County with 30 or more tests, 2007 to 2016, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Bexar County32 mi1976.6%0.6 pCi/L
Travis County82 mi4089.3%0.8 pCi/L
Nueces County104 mi450.0%0.6 pCi/L
Williamson County106 mi982.0%0.7 pCi/L
Bell County133 mi3514.3%1.1 pCi/L
Fort Bend County142 mi1173.4%0.2 pCi/L
Brazos County148 mi490.0%0.2 pCi/L
Brazoria County159 mi326.3%0.3 pCi/L
Wilson County ten-year laboratory totals, against Texas' pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestTexas, pooledChange from the row before
2008 to 201710.0%0.1 pCi/L0.1 pCi/L10.2%Level
2007 to 201610.0%0.1 pCi/L0.1 pCi/L10.4%Level
2006 to 201510.0%0.1 pCi/L0.1 pCi/L11.0%Level
2005 to 201410.0%0.1 pCi/L0.1 pCi/L10.6%First on file

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

Wilson County, Geology

The ground under Wilson County

Predicted

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).

USGS's geologic areas under Wilson County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
East Texas ProvinceCretaceous through Quaternary marine sandstone, shale, chalk, limestone, siltstone, clay, and lignite.Low6100%

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

Wilson County beside the ground around it

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.

Share of land by USGS radon potential: Wilson County, the 5 counties bordering it and Texas
AreaEPA zoneLow potentialModerate potentialHigh potential
Wilson CountyZone 3100%NoneNone
Karnes CountyZone 3100%NoneNone
Bexar CountyZone 3100%NoneNone
Atascosa CountyZone 3100%NoneNone
Guadalupe CountyZone 3100%NoneNone
Gonzales CountyZone 3100%NoneNone
Texas254 counties, pooled by land areaVaries72.4%26.8%0.5%

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

Local help

Wilson County, Local resources

Radon testing and mitigation in Wilson County

What it means

Wilson County, Questions

Questions about radon in Wilson County

Are radon levels high in Wilson County?

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.

Which counties border Wilson County?

Wilson County borders 5 counties: Karnes County, Bexar County, Atascosa County, Guadalupe County and Gonzales County.

Products

Wilson County, Products

Testing a home in Wilson County

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 monitors3

See every kit and monitor

Best radon monitors for Wilson County homes, compared

Explore

Wilson County, Bordering counties

Counties bordering Wilson County

Calculated by Radon411

Wilson County, Cities and towns

Cities and towns in Wilson County

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.

The cities and towns in Wilson County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Floresville9,105+25.2%16.2%
Elmendorfextends beyond Wilson County3,111+66.6%Counted whole
Nixonextends beyond Wilson County2,406+2.1%Counted whole
Poth2,014+10.1%3.6%
La Vernia1,499+38.2%2.7%
Stockdale1,494+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

Homes in Wilson County

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 in Wilson County, Texas, 2019 to 2023
HomesWilson CountyTexas
Housing units19,25911,890,808
Detached houses69%65%
In buildings of 5 or more2%21%
Mobile homes25%7%
Built before 19607%13%
Built since 200048%37%
Middle year built19991990
Owner-occupied86%63%

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