Skip to content
RADON411

Locations and reports

Radon Levels in Greene County, Missouri

EPA puts Greene County in Zone 2, its middle radon zone, and 27.1% of its 48 reported radon tests (2023) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

How to test this homeFind a certified tester

  • Share at 4+ pCi/L

    27.1%

    8.6 pts below MO

    Greene
    27.1%
    Missouri
    35.7%

    48 tests, 2023

  • Median result

    2.9pCi/L

    Below action level

    Greene
    2.9 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    48

    6th of 7 by tests

    Greene
    48
    St. Louis
    443

    Reported to CDC before any fix, 2023

  • EPA radon zone

    Zone 2

    Moderate potential

    1. 1
    2. Zone 2
    3. 3

    1 highest, 3 lowest

    EPA predicts 2 to 4 pCi/L indoors

  • Rank in Missouri

    6 of 7

    Lowest quarter

    Greene
    27.1%
    Clay
    44.6%

    By share, of 7 with 30+ tests

Read a result for Greene County

Starts at Greene County's median, 2.9 pCi/L

2.9pCi/L

EPA’s own thresholds; the figures are the area’s, never this home’s.

EPA’s reading of 2.9 pCi/L

Between 2 and 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 between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Greene County's median reported result, 2023.

Interpret this readingWhat a fix costs

The data

Greene County, At a glance

Greene County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Greene County is a county: EPA's forecast for it as a whole is an average indoor of 2 to 4 pCi/L (75 to 150 Bq/m³). It describes no single address, and homes above EPA's are found in every zone, this one included.

USGS geologic potential: Moderate across 100% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Greene County, 2023

Share of reported tests at or above 4 pCi/L, by year, Greene County
Share of reported tests at or above 4 pCi/L, by year, Greene County
YearShare of reported tests at or above 4 pCi/L
201429.9%
201525.0%
201623.4%
201725.8%
201842.1%
201938.1%
202031.4%
202130.8%
202228.7%
202327.1%

2023: 27.1%. Across these years the share ran from 23.4% to 42.1%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 48 tests reported to CDC for Greene County over 2023, many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.

Measured: CDC tracking data. Figure above: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Greene County, Compared

Greene County radon figures, compared

Calculated by Radon411

Greene County's 48 reported tests in 2023 had a middle value of 2.9 pCi/L and a maximum of 15.5 pCi/L, and 27.1% reached 4 pCi/L. Missouri as a whole (91 Missouri counties, pooled) comes to 35.7%: 8.6 points higher than here.

Among its state's counties it ranks 6th of 7 Missouri counties with 30 or more tests for the same period. Statewide for the same period, Clay County reported the highest share (44.6%) and St. Louis County the lowest (22.6%).

Below the action level, 17 tests (35.4%) came in under 2 pCi/L, against 36.6% statewide, and 18 tests (37.5%) fell between 2 and 4, against 27.7% statewide. The busiest year on file was 2015, with 88 tests reported; the quietest, 2019, had 21.

EPA's 1993 zone map puts Greene County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.

Over 9 years of annual figures the share fell 2.8 points, from 29.9% in 2014 to 27.1% in 2023; its peak was 42.1% in 2018.

Share of reported tests at or above 4 pCi/L by year, Greene County against Missouri2014 to 2023, years with 30 or more tests: Greene County 29.9% to 27.1%, the state's pooled share 35.7% in 2023.
Greene CountyMissouri, pooled
Share of reported tests at or above 4 pCi/L by year, Greene County against Missouri: data table
YearTestsGreene County, at or above 4 pCi/LMissouri, pooled
20148729.9%34.4%
20158825.0%27.6%
20167723.4%29.8%
20176225.8%37.0%
20183842.1%42.1%
20208631.4%33.2%
20213930.8%31.8%
20228728.7%40.8%
20234827.1%35.7%
Greene County against Missouri, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Greene County
Greene County4827.1%2.9 pCi/LThis county
Missouri, pooled91 counties, pooled1,41235.7%Not pooled+8.6 points
United States, pooled642 counties, pooled128,74033.4%Not pooled+6.3 points
Clay Countyhighest in the state8344.6%3.6 pCi/L+17.5 points
St. Louis Countylowest in the state44322.6%2.0 pCi/L−4.5 points
Polk County, MOborders it366.7%5.4 pCi/L+39.6 points
Dade County, MOborders it366.7%5.4 pCi/L+39.6 points
Christian County, MOborders it2343.5%2.7 pCi/L+16.4 points
Dallas County, MOborders it333.3%2.8 pCi/L+6.2 points
Lawrence County, MOborders it425.0%0.1 pCi/L−2.1 points
Webster County, MOborders it911.1%0.7 pCi/L−16.0 points
Where Greene County's reported results fell, 2023, beside Missouri and the United States
ResultGreene County testsGreene County shareMissouri shareU.S. shareAgainst Missouri
Under 2 pCi/L1735.4%36.6%41.4%−1.2 points
2 to 4 pCi/L1837.5%27.7%25.2%+9.8 points
4 pCi/L and above1327.1%35.7%33.4%−8.6 points
Greene County ranked among the 7 Missouri counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Clay County1 of 78344.6%3.6 pCi/L
Jackson County2 of 720444.1%3.4 pCi/L
Boone County3 of 76342.9%3.6 pCi/L
St. Charles County4 of 710340.8%3.4 pCi/L
Jefferson County5 of 73638.9%3.4 pCi/L
Greene County6 of 74827.1%2.9 pCi/L
St. Louis County7 of 744322.6%2.0 pCi/L
Greene County radon tests by year, against Missouri's pooled share
YearTestsAt or above 4 pCi/LMedianHighestMissouri, pooledChange from the row before
20234827.1%2.9 pCi/L15.5 pCi/L35.7%−1.6 points
20228728.7%2.5 pCi/L30.7 pCi/L40.8%−2.1 points
20213930.8%3.1 pCi/L17.6 pCi/L31.8%−0.6 points
20208631.4%2.3 pCi/L24.7 pCi/L33.2%−6.7 points
20192138.1%3.0 pCi/L60.1 pCi/L33.5%−4.0 points
20183842.1%3.0 pCi/L65.9 pCi/L42.1%+16.3 points
20176225.8%2.3 pCi/L20.1 pCi/L37.0%+2.4 points
20167723.4%1.7 pCi/L27.3 pCi/L29.8%−1.6 points
20158825.0%1.8 pCi/L19.0 pCi/L27.6%−4.9 points
20148729.9%2.1 pCi/L18.5 pCi/L34.4%First on file

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

Greene County, Geology

The ground under Greene County

Predicted

USGS's geologic map puts all of Greene County's mapped land in one class: moderate radon potential. The map puts 90.8% of Greene County in the area it calls Springfield Plateau and 9.2% in Salem Plateau. USGS gives both a radon index of 11, in the moderate band (9 to 11).

USGS's geologic areas under Greene County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Springfield PlateauMississippian limestone, shale, and sandstone.Moderate1190.8%
Salem PlateauOrdovician dolomite, sandstone, limestone, and shale.Moderate119.2%

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

Greene County beside the ground around it

Across Missouri 8.2% of the land is rated high; none of Greene County's is. Of the 6 counties that border it, none has as large a share of moderate-potential ground; Christian County comes nearest at 100%.

Share of land by USGS radon potential: Greene County, the 6 counties bordering it and Missouri
AreaEPA zoneLow potentialModerate potentialHigh potential
Greene CountyZone 2None100%None
Christian CountyZone 2None100%None
Webster CountyZone 2None100%None
Lawrence CountyZone 2None100%None
Polk CountyZone 2None100%None
Dallas CountyZone 2None100%None
Dade CountyZone 2None100%None
Missouri115 counties, pooled by land areaVaries5.8%86.0%8.2%

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

Local help

Greene County, Local resources

Radon testing and mitigation in Greene County

What Missouri's program says
Phone
573-751-6102
Email
radon@health.mo.gov

What it means

Greene County, Questions

Questions about radon in Greene County

Are radon levels high in Greene County?

In 2023, 27.1% of the radon tests reported to CDC for Greene County, Missouri were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.9 pCi/L. Of 7 Missouri counties with 30 or more tests for the same period, 5 reported a higher share; pooled, the state comes to 35.7%.

Which counties border Greene County?

Greene County borders 6 counties: Christian County, Webster County, Lawrence County, Polk County, Dallas County and Dade County.

Products

Greene County, Products

Testing a home in Greene County

In Greene County, 27.1% of 48 tests reported to CDC in 2023 reached 4 pCi/L, against 35.7% pooled across Missouri. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Greene County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Greene County homes, compared

Explore

Greene County, Bordering counties

Counties bordering Greene County

Calculated by Radon411

Greene County, Cities and towns

Cities and towns in Greene County

The Census Bureau estimates 309,286 residents in Greene County for July 1, 2025, 9,958 more than in 2020 (+3.3%). That works out to 458 people per square mile of land. Springfield, the largest place on its list (169,847 residents in all), extends beyond Greene County, so no share of the total is worked out for it. CDC's 48 reported tests for 2023 work out to 0.2 per 1,000 residents (2025 estimate), close to Missouri's 0.2.

From Springfield to Walnut Grove, CDC publishes no figure by town: each reads Greene County's.

The cities and towns in Greene County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Springfieldextends beyond Greene County169,847+0.4%Counted whole
Republicextends beyond Greene County22,404+19.5%Counted whole
Willard6,904+8.3%2.2%
Battlefield6,361+5.5%2.1%
Rogersvilleextends beyond Greene County5,754+47.7%Counted whole
Straffordextends beyond Greene County2,789+8.5%Counted whole
Fair Grove1,645+3.6%0.5%
Ash Grove1,532+1.0%0.5%
Walnut Grove636−1.9%0.2%

9 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 Greene County is counted whole, so it has no share.

Greene County, Homes

Homes in Greene County

Of Greene County's 137,930 homes, 71% are detached houses, against 70% across Missouri; 19% are in buildings of five or more homes. Half of its homes were built before 1982, close to Missouri's 1978: 21% date from before 1960 and 25% from 2000 or later. 57% of occupied homes are lived in by their owner (Missouri: 68%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Greene County, Missouri, 2019 to 2023
HomesGreene CountyMissouri
Housing units137,9302,809,501
Detached houses71%70%
In buildings of 5 or more19%13%
Mobile homes3%5%
Built before 196021%28%
Built since 200025%21%
Middle year built19821978
Owner-occupied57%68%

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