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Radon Levels in Hopkins County, Texas

EPA puts Hopkins 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

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  • Nearest county

    9.1%

    Smith County, 56 miles

    Smith
    9.1%
    Texas
    10.4%

    Share at 4+ pCi/L, 33 tests, 2007 to 2016

  • Ground above low

    None

    27.3 pts below Texas

    Hopkins
    0.0%
    Texas
    27.3%

    Share of land USGS rates moderate or high potential

  • Tests reported

    1

    Too few for a share

    Hopkins
    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 Hopkins 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.

Interpret this readingWhat a fix costs

The data

Hopkins County, At a glance

Hopkins County at a glance

Predicted: EPA radon zone

EPA Zone 3: lower predicted potential

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

CDC holds 1 reported test for Hopkins County over the 2008 to 2017 laboratory totals, a result of 5.0 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Hopkins County beside the counties around it is how this page reads it.

What these figures count

Only 1 test was reported to CDC for Hopkins 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

Hopkins County, Compared

Hopkins County radon figures, compared

Calculated by Radon411

CDC's largest figure for Hopkins County rests on 1 test over the 2008 to 2017 laboratory totals, 1 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 5.0 pCi/L, with a middle value of 5.0 pCi/L.

The nearest counties with a figure are Smith County (56 miles away) at 9.1%, Collin County (59 miles away) at 7.7% and Dallas County (75 miles away) at 8.7%. 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 Hopkins 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 Hopkins 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
Hunt County, TXborders it425.0%2.0 pCi/L
The nearest Texas counties to Hopkins County with 30 or more tests, 2007 to 2016, laboratory
CountyDistanceTestsAt or above 4 pCi/LMedian
Smith County56 mi339.1%0.8 pCi/L
Collin County59 mi2847.7%1.0 pCi/L
Dallas County75 mi6998.7%1.0 pCi/L
Denton County90 mi1817.2%0.9 pCi/L
Tarrant County104 mi31210.6%0.9 pCi/L
McLennan County146 mi4117.1%1.0 pCi/L
Brazos County177 mi490.0%0.2 pCi/L
Bell County184 mi3514.3%1.1 pCi/L
Hopkins County ten-year laboratory totals, against Texas' pooled share
PeriodTestsAt or above 4 pCi/LMedianHighestTexas, pooledChange from the row before
2008 to 20171100.0%5.0 pCi/L5.0 pCi/L10.2%Level
2007 to 20161100.0%5.0 pCi/L5.0 pCi/L10.4%Level
2006 to 20151100.0%5.0 pCi/L5.0 pCi/L11.0%Level
2005 to 20141100.0%5.0 pCi/L5.0 pCi/L10.6%First on file

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

Hopkins County, Geology

The ground under Hopkins County

Predicted

USGS's geologic map puts all of Hopkins 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 Hopkins 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.

Hopkins County beside the ground around it

Across Texas 0.5% of the land is rated high; none of Hopkins County's is. None of the 5 counties that border it has any moderate-potential ground either.

Share of land by USGS radon potential: Hopkins County, the 5 counties bordering it and Texas
AreaEPA zoneLow potentialModerate potentialHigh potential
Hopkins CountyZone 3100%NoneNone
Delta CountyZone 3100%NoneNone
Rains CountyZone 3100%NoneNone
Franklin CountyZone 3100%NoneNone
Wood CountyZone 3100%NoneNone
Hunt 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

Hopkins County, Local resources

Radon testing and mitigation in Hopkins County

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

Hopkins County, Questions

Questions about radon in Hopkins County

Are radon levels high in Hopkins County?

Over the 2008 to 2017 laboratory totals, 100.0% of the radon tests reported to CDC for Hopkins County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.0 pCi/L. Of the 8 nearest counties with a figure, within 184 miles, the share of tests at or above 4 pCi/L runs from 0.0% to 17.1%.

Which counties border Hopkins County?

Hopkins County borders 5 counties: Delta County, Rains County, Franklin County, Wood County and Hunt County.

Products

Hopkins County, Products

Testing a home in Hopkins County

No CDC figure names Hopkins County; the nearest county with one, Smith County (56 miles away), reported 9.1% 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 Hopkins County.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Hopkins County homes, compared

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Hopkins County, Bordering counties

Counties bordering Hopkins County

Calculated by Radon411

Hopkins County, Cities and towns

Cities and towns in Hopkins County

Hopkins County is growing: the Census Bureau puts it at 39,063 residents on July 1, 2025, up 6.1% from 36,833 in 2020. That works out to 51 people per square mile of land. Its largest town, Sulphur Springs, has 17,054 residents, 43.7% of the total. Together its 4 incorporated places hold 48.3% of those residents; the other 51.7% live outside any of them. 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 Sulphur Springs to Tira, CDC publishes no figure by town: each reads Hopkins County's.

The cities and towns in Hopkins County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Sulphur Springs17,054+6.8%43.7%
Como758+4.3%1.9%
Cumby726+6.5%1.9%
Tira343+7.5%0.9%

4 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).

Hopkins County, Homes

Homes in Hopkins County

Of Hopkins County's 15,793 homes, 74% are detached houses, against 65% across Texas; 13% are mobile homes. Half of its homes were built before 1984, close to Texas' 1990: 19% date from before 1960 and 28% from 2000 or later. 70% of occupied homes are lived in by their owner (Texas: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Hopkins County, Texas, 2019 to 2023
HomesHopkins CountyTexas
Housing units15,79311,890,808
Detached houses74%65%
In buildings of 5 or more8%21%
Mobile homes13%7%
Built before 196019%13%
Built since 200028%37%
Middle year built19841990
Owner-occupied70%63%

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