Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Jefferson County, Oregon
EPA puts Jefferson County in Zone 2, its middle radon zone, and only 3 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
19.7%
Marion County
- Marion
- 19.7%
- Deschutes
- 6.7%
4 of 6 neighbours have 30+ tests, 2016
Nearest county
10.0%
Wasco County, 37 miles
- Wasco
- 10.0%
- Oregon
- 21.5%
Share at 4+ pCi/L, 30 tests, 2016
Ground above low
85.5%
23.2 pts above Oregon
- Jefferson
- 85.5%
- Oregon
- 62.3%
Share of land USGS rates moderate or high potential
Tests reported
8
Too few for a share
- Jefferson
- 8
- Needed
- 30
2021
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Read a result for Jefferson 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
Jefferson County, At a glance
Jefferson County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Jefferson County is a
USGS geologic potential: Moderate across 85% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Jefferson County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 20.0% |
| 2015 | 0.0% |
| 2016 | 0.0% |
| 2017 | 0.0% |
| 2018 | 33.3% |
| 2019 | 0.0% |
| 2020 | 33.3% |
| 2021 | 0.0% |
| 2022 | 0.0% |
2022: 0.0%. Across these years the share ran from 0.0% to 33.3%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 3 tests were reported to CDC for Jefferson County over 2022, 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: 2022. Measured data period: 2005 to 2022 (every CDC figure on file).
Jefferson County, Compared
Jefferson County radon figures, compared
Calculated by Radon411CDC's largest figure for Jefferson County rests on 8 tests in 2021, 0 of them at or above 4 pCi/L, so each test moves its share by 12.5 points and no rank or comparison is drawn from it. Results reached as high as 2.4 pCi/L, with a middle value of 0.7 pCi/L.
Of the counties bordering it, 4 have a figure in 2016: Marion County reported the largest share at or above 4 pCi/L, 19.7%, and Deschutes County the smallest, 6.7%, with Wasco County at 10.0% and Linn County at 9.4% between. Farther out, Clackamas County (64 miles away) at 17.9%, Hood River County (66 miles away) at 20.8% and Multnomah County (88 miles away) at 28.6% have figures too. Pooled across 35 Oregon counties, 21.5% of reported tests reached that level; across every county in the country with a figure, 31.2%.
Statewide for the same period, Union County reported the highest share (39.1%) and Deschutes County the lowest (6.7%). EPA's 1993 map puts Jefferson County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 85% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Jefferson County, Geology
The ground under Jefferson County
PredictedMost of the ground under Jefferson County is one class on USGS's geologic map: 85.5% of its land is moderate radon potential, with 14.5% low. The map puts 55.9% of Jefferson County in the area it calls Deschutes Umatilla Plateau and 29.6% in Blue Mountains, with 2 smaller areas beside them. USGS gives both a radon index of 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Deschutes Umatilla Plateau | Tertiary basalt, basaltic breccia, tuffaceous sedimentary rocks and tuff. Elevated uranium in soils. | Moderate | 9 | 55.9% |
| Blue Mountains | Tertiary basalt and andesite, tuffaceous sedimentary rocks, and tuff. | Moderate | 9 | 29.6% |
| Cascade Range | Western Cascade Range is Tertiary andesite, basalt flows, and pyroclastic rocks. Eastern Cascades are late Tertiary to Quaternary basaltic and andesitic volcanic rocks. | Low | 7 | 10.9% |
| High Lava Plains | Tertiary and Quaternary basalt flows and Tertiary silicic ash-flow tuff. | Low | 7 | 3.6% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Jefferson County beside the ground around it
Jefferson County has more moderate-potential ground than Oregon as a whole: 85.5% of its land against 62.3%. Of the 6 counties that border it, 2 have more moderate-potential ground, Wheeler County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Jefferson County, Local resources
Radon testing and mitigation in Jefferson County
- Oregon Radon Awareness ProgramOregon Radon Awareness Program, run by Oregon Health Authority, offers free or discounted test kits, and answers questions about testing and mitigation in Oregon.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Oregon Radon Awareness Program provides a FREE short-term radon test kit to those living in areas of Oregon where little radon testing has been done.
- Compare kits
- Professionals in Oregon38 professionals are listed in Oregon.
What Oregon's program says
- Radon.program@dhsoha.state.or.us
What it means
Jefferson County, Questions
Questions about radon in Jefferson County
Are radon levels high in Jefferson County?
In 2022, 0.0% of the radon tests reported to CDC for Jefferson County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Of the counties bordering it, 4 have a figure in 2016: Marion County reported the largest share at or above 4 pCi/L, 19.7%, and Deschutes County the smallest, 6.7%, with Wasco County at 10.0% and Linn County at 9.4% between.
Which counties border Jefferson County?
Jefferson County borders 6 counties: Deschutes County, Wasco County, Wheeler County, Crook County, Linn County and Marion County.
Products
Jefferson County, Products
Testing a home in Jefferson County
No CDC figure names Jefferson County; the nearest county with one, Wasco County (37 miles away), reported 10.0% of its tests at or above 4 pCi/L in 2016, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Jefferson County; a long-term test tells the year-round average.
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
Monitor
lüft plug-in radon and indoor air quality monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Wi-Fi, Bluetooth
- App only
First reading: Within 90 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Jefferson County, Bordering counties
Counties bordering Jefferson County
Calculated by Radon411- Radon levels in Marion CountyEPA zone 3
19.7%at or above 4 pCi/L
Median 1.8 pCi/L · 508 tests
- Radon levels in Wasco CountyEPA zone 2
10.0%at or above 4 pCi/L
Median 0.8 pCi/L · 30 tests
- Radon levels in Linn CountyEPA zone 3
9.4%at or above 4 pCi/L
Median 1.0 pCi/L · 53 tests
- Radon levels in Deschutes CountyEPA zone 3
6.7%at or above 4 pCi/L
Median 0.8 pCi/L · 45 tests
- Radon levels in Crook CountyEPA zone 2
0.0%at or above 4 pCi/L
Median 0.8 pCi/L · 6 tests
- Radon levels in Wheeler CountyEPA zone 2
No CDC figure for 2016; its page reads it against its own neighbours.
Jefferson County, Cities and towns
Cities and towns in Jefferson County
The Census Bureau estimates 25,740 residents in Jefferson County for July 1, 2025, 1,158 more than in 2020 (+4.7%). That works out to 14 people per square mile of land. Its largest town, Madras, has 7,829 residents, 30.4% of the total. Together its 3 incorporated places hold 41.0% of those residents; the other 59.0% live outside any of them. Reported testing is thin here: 8 tests over 2021, or 0.3 for every 1,000 residents (2025 estimate), where Oregon as a whole comes to 1.0.
From Madras to Metolius, CDC publishes no figure by town: each reads Jefferson County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Madras | 7,829 | +4.5% | 30.4% |
| Culver | 1,689 | +5.2% | 6.6% |
| Metolius | 1,039 | +5.6% | 4.0% |
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).
Jefferson County, Homes
Homes in Jefferson County
Of Jefferson County's 10,455 homes, 74% are detached houses, against 63% across Oregon; 16% are mobile homes. Much of Jefferson County is recent building: 27% of its homes have gone up since 2000 and the middle year built is 1990, against 1980 for Oregon. 71% 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 | Jefferson County | Oregon |
|---|---|---|
| Housing units | 10,455 | 1,838,631 |
| Detached houses | 74% | 63% |
| In buildings of 5 or more | 4% | 17% |
| Mobile homes | 16% | 8% |
| Built before 1960 | 10% | 23% |
| Built since 2000 | 27% | 24% |
| Middle year built | 1990 | 1980 |
| 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.