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Radon Levels in Yamhill County, Oregon

EPA puts Yamhill County in Zone 2, its middle radon zone, and 21.2% of its 33 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

    21.2%

    2.3 pts above OR

    Yamhill
    21.2%
    Oregon
    18.9%

    33 tests, 2023

  • Median result

    1.6pCi/L

    Below action level

    Yamhill
    1.6 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2023

  • Tests reported

    33

    13th of 14 by tests

    Yamhill
    33
    Multnomah
    792

    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 Oregon

    4 of 14

    Top quarter

    Yamhill
    21.2%
    Hood River
    39.0%

    By share, of 14 with 30+ tests

Read a result for Yamhill County

Starts at Yamhill County's median, 1.6 pCi/L

1.6pCi/L

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

EPA’s reading of 1.6 pCi/L

Below 2 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 below 2 pCi/L, the level at which EPA says a fix should be considered. Yamhill County's median reported result, 2023.

Interpret this reading

The data

Yamhill County, At a glance

Yamhill County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Yamhill 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: Low across 52% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Yamhill County, 2023

Share of reported tests at or above 4 pCi/L, by year, Yamhill County
Share of reported tests at or above 4 pCi/L, by year, Yamhill County
YearShare of reported tests at or above 4 pCi/L
201436.5%
201532.6%
201620.0%
201718.0%
201823.8%
201913.5%
202014.3%
202115.5%
202229.4%
202321.2%

2023: 21.2%. Across these years the share ran from 13.5% to 36.5%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

These are the 33 tests reported to CDC for Yamhill 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

Yamhill County, Compared

Yamhill County radon figures, compared

Calculated by Radon411

Yamhill County's 33 reported tests in 2023 had a middle value of 1.6 pCi/L and a maximum of 35.1 pCi/L, and 21.2% reached 4 pCi/L. Oregon as a whole (28 Oregon counties, pooled) comes to 18.9%: 2.3 points lower than here.

Among its state's counties it ranks 4th of 14 Oregon counties with 30 or more tests for the same period. Statewide for the same period, Hood River County reported the highest share (39.0%) and Deschutes County the lowest (1.7%).

Below the action level, 17 tests (51.5%) came in under 2 pCi/L, against 59.5% statewide, and 9 tests (27.3%) fell between 2 and 4, against 21.6% statewide. The busiest year on file was 2016, with 255 tests reported; the quietest, 2023, had 33.

EPA's 1993 zone map puts Yamhill County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 52% of the county's land low radon potential.

Next door, the shares run from 10.1% in Polk County to 16.0% in Marion County, with Marion County, Clackamas County and Washington County below Yamhill County. Over 10 years of annual figures the share fell 15.3 points, from 36.5% in 2014 to 21.2% in 2023; its peak was 36.5% in 2014.

Share of reported tests at or above 4 pCi/L by year, Yamhill County against Oregon2014 to 2023, years with 30 or more tests: Yamhill County 36.5% to 21.2%, the state's pooled share 18.9% in 2023.
Yamhill CountyOregon, pooled
Share of reported tests at or above 4 pCi/L by year, Yamhill County against Oregon: data table
YearTestsYamhill County, at or above 4 pCi/LOregon, pooled
201410436.5%25.1%
201522132.6%27.4%
201625520.0%21.5%
201712218.0%19.2%
201812223.8%19.6%
20198913.5%20.2%
202015414.3%16.8%
20218415.5%16.3%
202215329.4%20.2%
20233321.2%18.9%
Yamhill County against Oregon, the United States and nearby counties, 2023
AreaTestsAt or above 4 pCi/LMedianDifference from Yamhill County
Yamhill County3321.2%1.6 pCi/LThis county
Oregon, pooled28 counties, pooled2,32918.9%Not pooled−2.3 points
United States, pooled642 counties, pooled128,74033.4%Not pooled+12.2 points
Hood River Countyhighest in the state4139.0%2.2 pCi/L+17.8 points
Deschutes Countylowest in the state601.7%0.9 pCi/L−19.5 points
Marion County, ORborders it19416.0%1.4 pCi/L−5.2 points
Clackamas County, ORborders it32115.9%1.6 pCi/L−5.3 points
Washington County, ORborders it39611.4%1.3 pCi/L−9.8 points
Polk County, ORborders it7910.1%1.4 pCi/L−11.1 points
Tillamook County, ORborders it119.1%1.5 pCi/L−12.1 points
Where Yamhill County's reported results fell, 2023, beside Oregon and the United States
ResultYamhill County testsYamhill County shareOregon shareU.S. shareAgainst Oregon
Under 2 pCi/L1751.5%59.5%41.4%−8.0 points
2 to 4 pCi/L927.3%21.6%25.2%+5.7 points
4 pCi/L and above721.2%18.9%33.4%+2.3 points
Yamhill County ranked among the 14 Oregon counties with 30 or more tests, by share at or above 4 pCi/L, 2023
CountyRankTestsAt or above 4 pCi/LMedian
Hood River County1 of 144139.0%2.2 pCi/L
Douglas County2 of 143333.3%1.8 pCi/L
Multnomah County3 of 1479227.8%2.0 pCi/L
Yamhill County4 of 143321.2%1.6 pCi/L
Jackson County5 of 144916.3%0.7 pCi/L
Marion County6 of 1419416.0%1.4 pCi/L
Clackamas County7 of 1432115.9%1.6 pCi/L
Benton County8 of 143215.6%0.9 pCi/L
Lane County9 of 145815.5%1.0 pCi/L
Washington County10 of 1439611.4%1.3 pCi/L
Polk County11 of 147910.1%1.4 pCi/L
Yamhill County radon tests by year, against Oregon's pooled share
YearTestsAt or above 4 pCi/LMedianHighestOregon, pooledChange from the row before
20233321.2%1.6 pCi/L35.1 pCi/L18.9%−8.2 points
202215329.4%1.7 pCi/L30.6 pCi/L20.2%+13.9 points
20218415.5%1.3 pCi/L21.5 pCi/L16.3%+1.2 points
202015414.3%1.5 pCi/L15.5 pCi/L16.8%+0.8 points
20198913.5%1.0 pCi/L16.2 pCi/L20.2%−10.3 points
201812223.8%1.9 pCi/L63.8 pCi/L19.6%+5.8 points
201712218.0%1.4 pCi/L14.1 pCi/L19.2%−2.0 points
201625520.0%1.4 pCi/L50.7 pCi/L21.5%−12.6 points
201522132.6%2.4 pCi/L83.9 pCi/L27.4%−3.9 points
201410436.5%2.1 pCi/L32.0 pCi/L25.1%First on file

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

Yamhill County, Geology

The ground under Yamhill County

Predicted

USGS's geologic map splits Yamhill County: 52.4% of its land is low radon potential and 47.6% moderate. The map puts 52.4% of Yamhill County in the area it calls Coast Range and 47.6% in Wilamette Valley. USGS gives the first a radon index of 7, in the low band (5 to 8), and the second 9, in the moderate band (9 to 11).

USGS's geologic areas under Yamhill County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Coast RangeNorthern Coast Range is marine sedimentary rocks and Tertiary mafic volcanic rocks. Southern Coast Range is Tertiary estuarine and marine sedimentary rocks, feldspathic and micaceous.Low752.4%
Wilamette ValleyGravelly to clayey alluvium with moderately elevated uranium content.Moderate947.6%

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

Yamhill County beside the ground around it

Oregon as a whole has more moderate-potential ground than Yamhill County: 62.3% of its land, against 47.6% here. Of the 5 counties that border it, 1 has more moderate-potential ground, Washington County the most at 48.2%.

Share of land by USGS radon potential: Yamhill County, the 5 counties bordering it and Oregon
AreaEPA zoneLow potentialModerate potentialHigh potential
Yamhill CountyZone 252.4%47.6%None
Washington CountyZone 251.8%48.2%None
Tillamook CountyZone 397.8%NoneNone
Polk CountyZone 371.9%28.1%None
Marion CountyZone 358.6%41.4%None
Clackamas CountyZone 386.6%13.4%None
Oregon36 counties, pooled by land areaVaries37.5%62.3%None

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

Local help

Yamhill County, Local resources

Radon testing and mitigation in Yamhill County

Listed radon businesses with an address in Yamhill County:

Listed radon professionals by town: Sheridan, Yamhill

What Oregon's program says
Email
Radon.program@dhsoha.state.or.us

What it means

Yamhill County, Questions

Questions about radon in Yamhill County

Are radon levels high in Yamhill County?

In 2023, 21.2% of the radon tests reported to CDC for Yamhill County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.6 pCi/L. Of 14 Oregon counties with 30 or more tests for the same period, 3 reported a higher share; pooled, the state comes to 18.9%.

Which counties border Yamhill County?

Yamhill County borders 5 counties: Washington County, Tillamook County, Polk County, Marion County and Clackamas County.

Products

Yamhill County, Products

Testing a home in Yamhill County

In Yamhill County, 21.2% of 33 tests reported to CDC in 2023 reached 4 pCi/L, against 18.9% pooled across Oregon. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Yamhill County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Yamhill County homes, compared

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Yamhill County, Bordering counties

Counties bordering Yamhill County

Calculated by Radon411

Yamhill County, Cities and towns

Cities and towns in Yamhill County

The Census Bureau estimates 110,024 residents in Yamhill County for July 1, 2025, 2,332 more than in 2020 (+2.2%). That works out to 154 people per square mile of land. Its largest town, McMinnville, has 34,647 residents, 31.5% of the total. Reported testing is thin here: 33 tests over 2023, or 0.3 for every 1,000 residents (2025 estimate), where Oregon as a whole comes to 0.5.

From McMinnville to Gaston, CDC publishes no figure by town: each reads Yamhill County's.

The cities and towns in Yamhill County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
McMinnville34,647+1.0%31.5%
Newberg26,896+5.6%24.4%
Sheridan6,243−2.8%5.7%
Lafayette4,705+6.3%4.3%
Dundee3,193−1.6%2.9%
Dayton2,647−0.8%2.4%
Carlton2,291+1.9%2.1%
Willaminaextends beyond Yamhill County2,276+1.1%Counted whole
Amity1,782+1.4%1.6%
Yamhill1,220+1.7%1.1%
Gastonextends beyond Yamhill County672−1.0%Counted whole

11 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 Yamhill County is counted whole, so it has no share.

Yamhill County, Homes

Homes in Yamhill County

Of Yamhill County's 40,744 homes, 68% are detached houses, against 63% across Oregon; 11% are in buildings of five or more homes. Much of Yamhill County is recent building: 28% of its homes have gone up since 2000 and the middle year built is 1989, against 1980 for Oregon. 70% of occupied homes are lived in by their owner (Oregon: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.

Homes in Yamhill County, Oregon, 2019 to 2023
HomesYamhill CountyOregon
Housing units40,7441,838,631
Detached houses68%63%
In buildings of 5 or more11%17%
Mobile homes10%8%
Built before 196018%23%
Built since 200028%24%
Middle year built19891980
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.