Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Josephine County, Oregon
EPA puts Josephine County in Zone 3, its lowest radon zone, and only 6 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
Share at 4+ pCi/L
21.3%
1.1 pts above OR
- Josephine
- 21.3%
- Oregon
- 20.2%
633 tests, 2022
Median result
1.3pCi/L
Below action level
- Josephine
- 1.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2022
Tests reported
633
3rd of 18 by tests
- Josephine
- 633
- Multnomah
- 2,679
Reported to CDC before any fix, 2022
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Rank in Oregon
7 of 18
Middle half
- Josephine
- 21.3%
- Tillamook
- 38.5%
By share, of 18 with 30+ tests
Read a result for Josephine County
Starts at Josephine County's median, 1.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.3 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Josephine County's median reported result, 2022.
The data
Josephine County, At a glance
Josephine County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Josephine County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 25.0% |
| 2015 | 0.0% |
| 2016 | 0.0% |
| 2017 | 0.0% |
| 2018 | 50.0% |
| 2019 | 33.3% |
| 2020 | 4.2% |
| 2021 | 0.0% |
| 2022 | 21.3% |
| 2023 | 0.0% |
2023: 0.0%. Across these years the share ran from 0.0% to 50.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 6 tests were reported to CDC for Josephine 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).
Josephine County, Compared
Josephine County radon figures, compared
Calculated by Radon411Josephine County's 633 reported tests in 2022 had a middle value of 1.3 pCi/L and a maximum of 15.6 pCi/L, and 21.3% reached 4 pCi/L. Oregon as a whole (33 Oregon counties, pooled) comes to 20.2%: 1.1 points lower than here.
The newest figure, in 2023, counts only 6 tests (0.0% at or above 4 pCi/L), too few to compare, so this reading uses the 633-test figure.
Among its state's counties it ranks 7th of 18 Oregon counties with 30 or more tests for the same period. Statewide for the same period, Tillamook County reported the highest share (38.5%) and Linn County the lowest (0.0%).
Below the action level, 381 tests (60.2%) came in under 2 pCi/L, against 57.2% statewide, and 117 tests (18.5%) fell between 2 and 4, against 22.5% statewide. The busiest year on file was 2022, with 633 tests reported; the quietest, 2018, had 2.
EPA's 1993 zone map puts Josephine County in Zone 3, a predicted county average under 2 pCi/L. USGS geology rates 100% of the county's land low radon potential.
Jackson County, the one bordering county with a figure for the same period, reported 15.1%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Josephine County, Geology
The ground under Josephine County
PredictedUSGS's geologic map puts all of Josephine County's mapped land in one class: low radon potential. All of it lies in the area the map calls Klamath Mountains, to which USGS gives a radon index of 7, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Klamath Mountains | Triassic to Jurassic metamorphic, volcanic, and sedimentary rocks with some Cretaceous intrusive igneous rocks. | Low | 7 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Josephine County beside the ground around it
Across Oregon 62.3% of the land is rated moderate; none of Josephine County's is. Of the 5 counties that border it, 1 has more moderate-potential ground, Siskiyou County, CA the most at 5.6%.
The map rates the ground, not the air in any home.
Local help
Josephine County, Local resources
Radon testing and mitigation in Josephine 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
Josephine County, Questions
Questions about radon in Josephine County
Are radon levels high in Josephine County?
In 2023, 0.0% of the radon tests reported to CDC for Josephine County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.2 pCi/L. Of 18 Oregon counties with 30 or more tests for the same period, 6 reported a higher share; pooled, the state comes to 20.2%.
Which counties border Josephine County?
Josephine County borders 5 counties: Curry County, OR, Jackson County, OR, Del Norte County, CA, Douglas County, OR and Siskiyou County, CA.
Products
Josephine County, Products
Testing a home in Josephine County
In Josephine County, 21.3% of 633 tests reported to CDC in 2022 reached 4 pCi/L, against 20.2% pooled across Oregon. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Josephine County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-3786 rechargeable radon monitor with a 3.5-inch color screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Josephine County, Bordering counties
Counties bordering Josephine County
Calculated by Radon411- Radon levels in Curry County, OREPA zone 3
25.0%at or above 4 pCi/L
Median 1.1 pCi/L · 12 tests · 3.7 points above Josephine County
- Radon levels in Jackson County, OREPA zone 3
15.1%at or above 4 pCi/L
Median 0.7 pCi/L · 258 tests · 6.2 points below Josephine County
- Radon levels in Douglas County, OREPA zone 3
0.0%at or above 4 pCi/L
Median 0.7 pCi/L · 15 tests · 21.3 points below Josephine County
- Radon levels in Del Norte County, CAEPA zone 3
No CDC figure for 2022; its page reads it against its own neighbours.
- Radon levels in Siskiyou County, CAEPA zone 3
No CDC figure for 2022; its page reads it against its own neighbours.
Josephine County, Cities and towns
Cities and towns in Josephine County
Josephine County's population has barely moved since 2020: 87,867 residents on July 1, 2025 against 88,214 then, by the Census Bureau's estimates. That works out to 54 people per square mile of land. Its largest town, Grants Pass, has 39,239 residents, 44.7% of the total. Together its 2 incorporated places hold 47.0% of those residents; the other 53.0% live outside any of them. Testing is reported here more often than across the state: CDC's 633 reported tests for 2022 come to 7.2 for every 1,000 residents (2025 estimate), against 1.6 for Oregon.
From Grants Pass to Cave Junction, CDC publishes no figure by town: each reads Josephine County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Grants Pass | 39,239 | +0.1% | 44.7% |
| Cave Junction | 2,074 | −0.5% | 2.4% |
2 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).
Josephine County, Homes
Homes in Josephine County
Of Josephine County's 39,217 homes, 71% are detached houses, against 63% across Oregon; 16% are mobile homes. Half of its homes were built before 1981, close to Oregon's 1980: 19% date from before 1960 and 24% from 2000 or later. 72% 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 | Josephine County | Oregon |
|---|---|---|
| Housing units | 39,217 | 1,838,631 |
| Detached houses | 71% | 63% |
| In buildings of 5 or more | 4% | 17% |
| Mobile homes | 16% | 8% |
| Built before 1960 | 19% | 23% |
| Built since 2000 | 24% | 24% |
| Middle year built | 1981 | 1980 |
| Owner-occupied | 72% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.