Locations and reports
Radon Levels in Montgomery County, Missouri
What this means for you
- Your area: EPA rates Montgomery County Zone 2, the middle of its three radon zones. That is a prediction for the whole county, and homes with elevated levels occur in all three zones.
- Local tests: Of 2 buildings with radon tests reported to CDC for Montgomery County (2023), 50.0% were at or above 4 pCi/L, EPA's action level.
- Your home: The only way to know your home’s level is to test it.
pCi/L (picocuries per liter) is the unit radon is measured in. EPA recommends fixing a home at 4 pCi/L or above, its action level.
In 2023, 50.0% of the radon tests reported to CDC for Montgomery County, Missouri came back at or above the EPA action level of 4 pCi/L, and the median result was 3.5 pCi/L. EPA's Map of Radon Zones places the county in Zone 2, moderate predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
EPA predicts an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³) across the county as a whole.
This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.
USGS geologic potential: Moderate across 100% of the county's land area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Montgomery County, 2023
- Buildings tested
- 2
- At or above 4 pCi/L
- 50.0%
- Median result
- 3.5 pCi/L
Distribution of tested buildings, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.
Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Montgomery County, In figures
Montgomery County in figures
What the published data says about Montgomery County, in words. A zone and a share of tests describe an area, never the level in any one home.
Predicted
PredictedEPA places Montgomery County in Zone 2, moderate predicted potential, as it does 96 other counties of Missouri's 115.
Of the 7 bordering counties, EPA places Audrain County, Callaway County, Gasconade County, Lincoln County, Osage County, Pike County and Warren County in Zone 2.
Reported tests
MeasuredCDC has annual figures for Montgomery County for 8 years, 2015 to 2023. In 2023, 50.0% of reported tests were at or above 4 pCi/L.
Across those years the share ranged from 0.0% (2017) to 100.0% (2018). Few tests in a year can move it a long way.
Local record
Missouri's radon program is the Missouri Radon Program, run by Missouri Department of Health and Senior Services; its contacts are under Local resources.
The county's largest incorporated places are Montgomery City, Wellsville and Jonesburg; the figures here cover them as part of the county.
Montgomery County, Reported testing
Reported testing over time
MeasuredNo figures are published for 2019. The axis keeps the space for the missing year and the line is not drawn across it.
| Year | Median reported result | Highest reported result | Share of tests at or above 4 pCi/L |
|---|---|---|---|
| 2015 | 1.3 pCi/L | 1.3 pCi/L | 0.0% |
| 2016 | 1.1 pCi/L | 3.2 pCi/L | 0.0% |
| 2017 | 2.0 pCi/L | 3.5 pCi/L | 0.0% |
| 2018 | 7.0 pCi/L | 7.0 pCi/L | 100.0% |
| 2020 | 2.3 pCi/L | 4.1 pCi/L | 50.0% |
| 2021 | 2.1 pCi/L | 6.3 pCi/L | 33.3% |
| 2022 | 2.6 pCi/L | 8.0 pCi/L | 14.3% |
| 2023 | 3.5 pCi/L | 4.4 pCi/L | 50.0% |
What these figures count
Every percentage here is a share of radon tests reported to CDC for Montgomery County in 2023. It is not a share of homes in Montgomery County, and it is not a random sample: it counts only the tests people chose to run and that were reported.
The shares and the median are calculated from pre-mitigation tests. CDC also reports the number of buildings tested (2), a different count, so the two totals are not interchangeable.
Montgomery County, Comparison
How Montgomery County compares
MeasuredMontgomery County's own published CDC figures beside those of the counties that border it, for the same period.
Share of reported tests at or above 4 pCi/L
Measured2023, highest first. Each county’s own published CDC figure.
- Audrain CountyMOTest count not published100.0%
- Warren CountyMO7 tests57.1%
- Gasconade CountyMOTest count not published50.0%
- Montgomery CountyThis pageTest count not published50.0%
- Lincoln CountyMO16 tests43.8%
- Callaway CountyMO13 tests30.8%
Published for 2023 without this measure: Pike County, MO.
Median reported result
Measured2023, highest first. Each county’s own published CDC figure.
- Gasconade CountyMOTest count not published11.1 pCi/L
- Audrain CountyMOTest count not published9.7 pCi/L
- Warren CountyMO7 tests5.7 pCi/L
- Montgomery CountyThis pageTest count not published3.5 pCi/L
- Callaway CountyMO13 tests2.8 pCi/L
- Lincoln CountyMO16 tests2.8 pCi/L
- Pike CountyMOTest count not published2.1 pCi/L
Each figure is that county’s own published CDC figure for 2023, counting radon tests reported to CDC, not homes. Montgomery County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. No published CDC figure for 2023: Osage County, MO. Every Missouri county’s own figure is in the Missouri county table.
CDC publishes this figure only for counties here, so there is no state or national number to compare Montgomery County, Missouri with.
Montgomery County, Bordering counties
Counties bordering Montgomery County
Calculated by Radon4117 counties share a boundary with Montgomery County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.
- Warren CountyMOZone 2: Moderate predicted potential
- Audrain CountyMOZone 2: Moderate predicted potential
- Callaway CountyMOZone 2: Moderate predicted potential
- Lincoln CountyMOZone 2: Moderate predicted potential
- Gasconade CountyMOZone 2: Moderate predicted potential
- Pike CountyMOZone 2: Moderate predicted potential
- Osage CountyMOZone 2: Moderate predicted potential
Montgomery County, Local resources
Local resources in Missouri
Who to ask in Missouri: the state's radon program, test kits and professionals.
Missouri Radon Program
Missouri Department of Health and Senior Services
Missouri’s radon program answers questions about testing, mitigation and the rules where you live.
- Phone
- 573-751-6102
- radon@health.mo.gov
Test kits
The program says: Free radon test kits are available for Missouri residents (limit one per household).
Radon professionals
6 professionals are listed in Missouri.
Professionals in MissouriMontgomery County, Cities and towns
Cities and towns in Montgomery County
The radon figures on this page are for Montgomery County as a whole. They do not differ by city or town.
- Montgomery City
- Wellsville
- Jonesburg
- New Florence
- Bellflower
- High Hill
- Middletown
- Rhineland
- McKittrick
9 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.
Montgomery County, Questions
Questions about radon in Montgomery County
Common questions8 questions, answered from the figures above
Are radon levels high in Montgomery County?
In 2023, 50.0% of the radon tests reported to CDC for Montgomery County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.5 pCi/L. That is a share of reported tests, not of homes. EPA places Montgomery County in Zone 2, moderate predicted potential, a predicted average indoor screening level 2 to 4 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.
How do I get a radon test in Montgomery County?
EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No certified tester listed on Radon411 names Montgomery County as a service area yet. The Missouri radon program is the place to ask about certified testers and any test kit offer it runs.
How to test a homeTest kits comparedFree and low-cost kits by stateMissouri radon program
Who does radon mitigation in Montgomery County?
No listed mitigator names Montgomery County as a service area yet; the Missouri directory lists 6 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether Missouri requires one.
How radon mitigation worksWhat mitigation costsMitigators in Missouri
What EPA radon zone is Montgomery County in?
EPA places Montgomery County, Missouri in Zone 2, which EPA describes as moderate predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.
Should I test my home in Montgomery County?
Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.
When is the best time of year to test?
EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.
What does it cost to test?
EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.
Which counties border Montgomery County?
Montgomery County borders 7 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.
What these figures mean if you own, buy, sell or rent
The reported-test figures on this page describe Montgomery County, Missouri in 2023. They describe tests other people carried out in other buildings, and none of them measures yours.
- How to test a home
If you own your home
Test the lowest lived-in level; a short-term kit screens in days, a long-term kit reflects the year.
- Buying a house: radon guide
If you are buying
Ask for past results and any system's post-mitigation test, and test during the sale.
- Selling a house: radon guide
If you are selling
Testing before you list puts the timing in your hands; disclosure rules differ by state.
- Radon in rental homes
If you rent, or rent out a home
A tenant can test; a fix is the owner's to make, and duties differ by state.
How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.
Montgomery County, Products
Testing and mitigation products
Whatever the figures for Montgomery County show, only a test tells you about one home.
Testing
- Short-term test kitsPassive detectors exposed for a few days under closed-building conditions, then analyzed by a lab.
- Long-term test kitsDetectors exposed for more than 90 days, for a closer picture of the annual average.
- Continuous monitorsPowered devices that log radon on a repeating cycle, often used for transaction tests.
- Digital detectorsConsumer devices that display a running radon reading without a lab.
- Water radon testsKits for radon dissolved in well water, analyzed by a lab.
Mitigation
- Mitigation fansThe inline fan that keeps a soil depressurization system running, sized by the installer.
- System indicatorsU-tube manometers and fan alarms that show whether a mitigation system is still working.
- Sealing materialsCrack, joint and sump sealing used alongside a mitigation system, not instead of one.
Montgomery County / Next steps
What to do next
Learn
Know what radon is
What radon is, how it gets indoors, and why a county zone is not a reading for your home.
Learn about radonTest
Test the building you live in
Short-term or long-term, where the device goes, and closed-house conditions.
How to testFix
Bring a high level down
How a mitigation system works, and the retest that confirms it.
How mitigation worksFind a pro
Hire a certified professional
Measurement and mitigation professionals by state, with their certifications.
Find a professional
Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.