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 Madison County, Texas
EPA puts Madison 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
0.0%
Brazos County
- Brazos
- 0.0%
1 of 6 neighbours have 30+ tests, 2007 to 2016
Nearest county
0.0%
Brazos County, 31 miles
- Brazos
- 0.0%
- Texas
- 10.4%
Share at 4+ pCi/L, 49 tests, 2007 to 2016
Ground above low
None
27.3 pts below Texas
- Madison
- 0.0%
- Texas
- 27.3%
Share of land USGS rates moderate or high potential
Tests reported
1
Too few for a share
- Madison
- 1
- Needed
- 30
2008 to 2017, laboratory
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 Madison 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
Madison County, At a glance
Madison 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
Radon tests reported for Madison County, 2008 to 2017, laboratory
CDC holds 1 reported test for Madison County over the 2008 to 2017 laboratory totals, a result of 1.5 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Madison County beside the counties around it is how this page reads it.
What these figures count
Only 1 test was reported to CDC for Madison 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).
Madison County, Compared
Madison County radon figures, compared
Calculated by Radon411CDC's largest figure for Madison 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 1.5 pCi/L, with a middle value of 1.5 pCi/L.
Brazos County, the one bordering county with a figure over the 2007 to 2016 laboratory totals, reported 0.0% of its tests at or above 4 pCi/L. Farther out, Montgomery County (52 miles away) at 7.1%, Harris County (83 miles away) at 3.1% and McLennan County (86 miles away) at 17.1% 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 Madison 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.
Madison County, Geology
The ground under Madison County
PredictedUSGS's geologic map puts all of Madison 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.
Madison County beside the ground around it
Across Texas 0.5% of the land is rated high; none of Madison 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
Madison County, Local resources
Radon testing and mitigation in Madison 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
Madison County, Questions
Questions about radon in Madison County
Are radon levels high in Madison County?
Over the 2008 to 2017 laboratory totals, 0.0% of the radon tests reported to CDC for Madison County, Texas were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Brazos County, the one bordering county with a figure over the 2007 to 2016 laboratory totals, reported 0.0% of its tests at or above 4 pCi/L.
Which counties border Madison County?
Madison County borders 6 counties: Leon County, Walker County, Grimes County, Brazos County, Houston County and Robertson County.
Products
Madison County, Products
Testing a home in Madison County
No CDC figure names Madison County; the nearest county with one, Brazos County (31 miles away), reported 0.0% 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 Madison 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
MonitorX-Sense
XR0A-iR Wi-Fi battery radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Wi-Fi
- Screen, app
Method: Alpha spectrometry
First reading: Within 24 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Madison County, Bordering counties
Counties bordering Madison County
Calculated by Radon411- Radon levels in Walker CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.5 pCi/L · 7 tests
- Radon levels in Grimes CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
- Radon levels in Brazos CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.2 pCi/L · 49 tests
- Radon levels in Robertson CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.8 pCi/L · 7 tests
- Radon levels in Leon CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
- Radon levels in Houston CountyEPA zone 3
No CDC figure for 2007 to 2016; its page reads it against its own neighbours.
Madison County, Cities and towns
Cities and towns in Madison County
Madison County is growing: the Census Bureau puts it at 14,226 residents on July 1, 2025, up 5.7% from 13,457 in 2020. That works out to 31 people per square mile of land. Its largest town, Madisonville, has 4,605 residents, 32.4% of the total. Reported testing is thin here: 1 test over 2008 to 2017, or 0.1 for every 1,000 residents (2025 estimate), where Texas as a whole comes to 0.1.
From Madisonville to Midway, CDC publishes no figure by town: each reads Madison County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Madisonville | 4,605 | +4.3% | 32.4% |
| Normangeeextends beyond Madison County | 563 | +11.3% | Counted whole |
| Midway | 191 | +9.8% | 1.3% |
3 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 Madison County is counted whole, so it has no share.
Madison County, Homes
Homes in Madison County
Of Madison County's 5,095 homes, 65% are detached houses, against 65% across Texas; 25% are mobile homes. Half of its homes were built before 1984, close to Texas' 1990: 18% date from before 1960 and 28% from 2000 or later. 71% 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 | Madison County | Texas |
|---|---|---|
| Housing units | 5,095 | 11,890,808 |
| Detached houses | 65% | 65% |
| In buildings of 5 or more | 3% | 21% |
| Mobile homes | 25% | 7% |
| Built before 1960 | 18% | 13% |
| Built since 2000 | 28% | 37% |
| Middle year built | 1984 | 1990 |
| Owner-occupied | 71% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.