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Radon Levels in Klamath County, Oregon

EPA puts Klamath County in Zone 2, its middle radon zone, and only 13 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.

Data checked By Radon411Methodology

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  • Share at 4+ pCi/L

    5.3%

    20.1 pts below OR

    Klamath
    5.3%
    Oregon
    25.4%

    38 tests, 2008 to 2017

  • Median result

    0.4pCi/L

    Below action level

    Klamath
    0.4 pCi/L
    EPA
    4.0 pCi/L

    Midpoint of the tests, 2008 to 2017

  • Tests reported

    38

    18th of 23 by tests

    Klamath
    38
    Multnomah
    12,330

    Reported to CDC before any fix, 2008 to 2017

  • 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

    22 of 23

    Lowest quarter

    Klamath
    5.3%
    Union
    42.0%

    By share, of 23 with 30+ tests

Read a result for Klamath County

Starts at Klamath County's median, 0.4 pCi/L

0.4pCi/L

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

EPA’s reading of 0.4 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. Klamath County's median reported result, 2008 to 2017.

Interpret this reading

The data

Klamath County, At a glance

Klamath County at a glance

Predicted: EPA radon zone

EPA Zone 2: moderate predicted potential

Klamath 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 72% of the county's area

Predicted: EPA Map of Radon Zones

Measured: tests reported to CDC

Radon tests reported for Klamath County, 2023

Share of reported tests at or above 4 pCi/L, by year, Klamath County
Share of reported tests at or above 4 pCi/L, by year, Klamath County
YearShare of reported tests at or above 4 pCi/L
201428.6%
20150.0%
201642.9%
201716.7%
20180.0%
20190.0%
202020.0%
20217.1%
20220.0%
202315.4%

2023: 15.4%. Across these years the share ran from 0.0% to 42.9%. Each column counts radon tests reported to CDC that year, not homes.

What these figures count

Only 13 tests were reported to CDC for Klamath County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).

How to read these figures

Klamath County, Compared

Klamath County radon figures, compared

Calculated by Radon411

Klamath County reports fewer high tests than Oregon overall. 5.3% of its 38 tests over the 2008 to 2017 laboratory totals were at or above 4 pCi/L. That is 20.1 points below the 25.4% pooled from 34 Oregon counties.

The newest figure, in 2023, counts only 13 tests (15.4% at or above 4 pCi/L), too few to compare, so this reading uses the 38-test figure.

Ordered from highest share down, it comes 22nd of 23 Oregon counties with 30 or more tests for the same period. Nationally, every county with a figure for the same period pools to 35.7%; Klamath County sits 30.4 points below it.

Next door, the shares run from 3.8% in Deschutes County to 9.1% in Lane County, with Deschutes County below Klamath County. The reported tests do not follow EPA's Zone 2 label for Klamath County (predicted average between 2 and 4 pCi/L): 5.3% of them reached 4 pCi/L, fewer than that label suggests.

Half the tests came in under 0.4 pCi/L and half over it; the single highest reached 13.1 pCi/L. The rest split 86.8% under 2 pCi/L and 7.9% from 2 to 4 (Oregon: 51.9% and 22.7%).

The busiest year on file was 2021, with 14 tests reported; the quietest, 2017, had 6.

Klamath County against Oregon, the United States and nearby counties, 2008 to 2017, laboratory
AreaTestsAt or above 4 pCi/LMedianDifference from Klamath County
Klamath County385.3%0.4 pCi/LThis county
Oregon, pooled34 counties, pooled23,95125.4%Not pooled+20.1 points
United States, pooled2,661 counties, pooled2,013,54435.7%Not pooled+30.4 points
Union Countyhighest in the state11242.0%3.0 pCi/L+36.7 points
Crook Countylowest in the state375.4%0.9 pCi/L+0.1 points
Siskiyou County, CAborders it825.0%1.1 pCi/L+19.7 points
Lane County, ORborders it4059.1%0.9 pCi/L+3.8 points
Douglas County, ORborders it348.8%0.6 pCi/L+3.5 points
Jackson County, ORborders it1135.3%1.0 pCi/LLevel
Deschutes County, ORborders it1593.8%0.7 pCi/L−1.5 points
Lake County, ORborders it40.0%0.3 pCi/L−5.3 points
Where Klamath County's reported results fell, 2008 to 2017, laboratory, beside Oregon and the United States
ResultKlamath County testsKlamath County shareOregon shareU.S. shareAgainst Oregon
Under 2 pCi/L3386.8%51.9%39.6%+34.9 points
2 to 4 pCi/L37.9%22.7%24.7%−14.8 points
4 pCi/L and above25.3%25.4%35.7%−20.1 points
Klamath County ranked among the 23 Oregon counties with 30 or more tests, by share at or above 4 pCi/L, 2008 to 2017, laboratory
CountyRankTestsAt or above 4 pCi/LMedian
Umatilla County13 of 233411.8%1.9 pCi/L
Washington County14 of 233,33810.1%1.0 pCi/L
Josephine County15 of 233010.0%0.7 pCi/L
Linn County16 of 231169.5%1.0 pCi/L
Lane County17 of 234059.1%0.9 pCi/L
Douglas County18 of 23348.8%0.6 pCi/L
Wasco County19 of 23365.6%1.0 pCi/L
Crook County20 of 23375.4%0.9 pCi/L
Jackson County21 of 231135.3%1.0 pCi/L
Klamath County22 of 23385.3%0.4 pCi/L
Deschutes County23 of 231593.8%0.7 pCi/L
Klamath County radon tests by year, against Oregon's pooled share
YearTestsAt or above 4 pCi/LMedianHighestOregon, pooledChange from the row before
20231315.4%1.4 pCi/L10.7 pCi/L18.9%+15.4 points
2022120.0%0.2 pCi/L0.6 pCi/L20.2%−7.1 points
2021147.1%0.5 pCi/L58.0 pCi/L16.3%−12.9 points
20201020.0%1.3 pCi/L6.6 pCi/L16.8%+20.0 points
201980.0%0.2 pCi/L1.0 pCi/L20.2%Level
2018110.0%0.6 pCi/L2.4 pCi/L19.6%−16.7 points
2017616.7%0.5 pCi/L5.7 pCi/L19.2%−26.2 points
2016742.9%1.6 pCi/L27.3 pCi/L21.5%+42.9 points
201590.0%0.9 pCi/L2.2 pCi/L27.4%−28.6 points
2014728.6%1.3 pCi/L14.3 pCi/L25.1%First on file

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

Klamath County, Geology

The ground under Klamath County

Predicted

USGS's geologic map splits Klamath County: 71.6% of its land is moderate radon potential and 28.4% low. The map puts 71.5% of Klamath County in the area it calls Northern Basin and Range and 23.7% in Cascade Range, with one smaller area beside them. USGS gives the first a radon index of 9, in the moderate band (9 to 11), and the second 7, in the low band (5 to 8).

USGS's geologic areas under Klamath County
AreaThe rock, in USGS's wordsPotentialRadon indexShare of land
Northern Basin and RangeBasalt, andesite, rhyolite, tuffaceous sedimentary rocks. Low soil uranium content in the western part, uranium-bearing volcanic rocks and uranium deposits in the eastern part of the province.Moderate971.5%
Cascade RangeWestern Cascade Range is Tertiary andesite, basalt flows, and pyroclastic rocks. Eastern Cascades are late Tertiary to Quaternary basaltic and andesitic volcanic rocks.Low723.7%
High Lava PlainsTertiary and Quaternary basalt flows and Tertiary silicic ash-flow tuff.Low74.8%

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

Klamath County beside the ground around it

On moderate-potential ground Klamath County is close to Oregon as a whole: 71.6% of its land against 62.3%. Of the 7 counties that border it, 1 has more moderate-potential ground, Lake County the most at 85.8%.

Share of land by USGS radon potential: Klamath County, the 7 counties bordering it and Oregon
AreaEPA zoneLow potentialModerate potentialHigh potential
Klamath CountyZone 228.4%71.6%None
Jackson CountyZone 3100%NoneNone
Lake CountyZone 214.2%85.8%None
Douglas CountyZone 399.7%NoneNone
Deschutes CountyZone 396.0%4.0%None
Lane CountyZone 389.8%10.0%None
Siskiyou County, CAZone 394.4%5.6%None
Modoc County, CAZone 355.4%44.6%None
Oregon36 counties, pooled by land areaVaries37.5%62.3%None

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

Local help

Klamath County, Local resources

Radon testing and mitigation in Klamath County

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

What it means

Klamath County, Questions

Questions about radon in Klamath County

Are radon levels high in Klamath County?

In 2023, 15.4% of the radon tests reported to CDC for Klamath County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.4 pCi/L. Of 23 Oregon counties with 30 or more tests for the same period, 21 reported a higher share; pooled, the state comes to 25.4%.

Which counties border Klamath County?

Klamath County borders 7 counties: Jackson County, OR, Lake County, OR, Douglas County, OR, Deschutes County, OR, Lane County, OR, Siskiyou County, CA and Modoc County, CA.

Products

Klamath County, Products

Testing a home in Klamath County

In Klamath County, 5.3% of 38 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 25.4% pooled across Oregon. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Klamath County; a long-term test tells the year-round average.

Test kits and monitors3

See every kit and monitor

Best radon monitors for Klamath County homes, compared

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Klamath County, Bordering counties

Counties bordering Klamath County

Calculated by Radon411

Klamath County, Cities and towns

Cities and towns in Klamath County

The Census Bureau estimates 70,274 residents in Klamath County for July 1, 2025, 650 more than in 2020 (+0.9%). That works out to 12 people per square mile of land. Its largest town, Klamath Falls, has 22,111 residents, 31.5% of the total. Together its 5 incorporated places hold 35.4% of those residents; the other 64.6% live outside any of them. Reported testing is thin here: 38 tests over 2008 to 2017, or 0.5 for every 1,000 residents (2025 estimate), where Oregon as a whole comes to 5.6.

From Klamath Falls to Bonanza, CDC publishes no figure by town: each reads Klamath County's.

The cities and towns in Klamath County by residents, July 1, 2025
PlaceResidentsSince 2020Share of residents
Klamath Falls22,111+1.0%31.5%
Merrill865+0.1%1.2%
Chiloquin770+0.1%1.1%
Malin736+0.5%1.0%
Bonanza417+1.7%0.6%

5 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).

Klamath County, Homes

Homes in Klamath County

Of Klamath County's 33,004 homes, 71% are detached houses, against 63% across Oregon; 13% are mobile homes. Half of its homes were built before 1975, close to Oregon's 1980: 31% date from before 1960 and 17% from 2000 or later. 69% 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 Klamath County, Oregon, 2019 to 2023
HomesKlamath CountyOregon
Housing units33,0041,838,631
Detached houses71%63%
In buildings of 5 or more6%17%
Mobile homes13%8%
Built before 196031%23%
Built since 200017%24%
Middle year built19751980
Owner-occupied69%63%

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