Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
Locations and reports
Radon Levels in Tillamook County, Oregon
EPA puts Tillamook County in Zone 3, its lowest radon zone, and only 11 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
19.8%
3.5 pts above OR
- Tillamook
- 19.8%
- Oregon
- 16.3%
126 tests, 2021
Median result
1.4pCi/L
Below action level
- Tillamook
- 1.4 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2021
Tests reported
126
9th of 19 by tests
- Tillamook
- 126
- Multnomah
- 1,623
Reported to CDC before any fix, 2021
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
5 of 19
Top quarter
- Tillamook
- 19.8%
- Umatilla
- 34.8%
By share, of 19 with 30+ tests
Read a result for Tillamook County
Starts at Tillamook County's median, 1.4 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.4 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. Tillamook County's median reported result, 2021.
The data
Tillamook County, At a glance
Tillamook County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 98% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Tillamook County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 14.3% |
| 2015 | 0.0% |
| 2016 | 18.2% |
| 2017 | 28.6% |
| 2018 | 8.3% |
| 2019 | 20.0% |
| 2020 | 12.5% |
| 2021 | 19.8% |
| 2022 | 38.5% |
| 2023 | 9.1% |
2023: 9.1%. Across these years the share ran from 0.0% to 38.5%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 11 tests were reported to CDC for Tillamook 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).
Tillamook County, Compared
Tillamook County radon figures, compared
Calculated by Radon411Tillamook County's 126 reported tests in 2021 had a middle value of 1.4 pCi/L and a maximum of 61.1 pCi/L, and 19.8% reached 4 pCi/L. Oregon as a whole (33 Oregon counties, pooled) comes to 16.3%: 3.5 points lower than here.
The newest figure, in 2023, counts only 11 tests (9.1% at or above 4 pCi/L), too few to compare, so this reading uses the 126-test figure.
Among its state's counties it ranks 5th of 19 Oregon counties with 30 or more tests for the same period. Statewide for the same period, Umatilla County reported the highest share (34.8%) and Deschutes County the lowest (3.6%).
Below the action level, 80 tests (63.5%) came in under 2 pCi/L, against 62.9% statewide, and 21 tests (16.7%) fell between 2 and 4, against 20.8% statewide. The busiest year on file was 2021, with 126 tests reported; the quietest, 2015, had 6.
EPA's 1993 zone map puts Tillamook County in Zone 3, a predicted county average under 2 pCi/L. USGS geology rates 98% of the county's land low radon potential.
Next door, the shares run from 9.4% in Lincoln County to 30.3% in Clatsop County, with Washington County, Yamhill County and Columbia County below Tillamook County.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Tillamook County, Geology
The ground under Tillamook County
PredictedUSGS's geologic map puts all of Tillamook County's mapped land in one class: low radon potential. 97.8% of it lies in the area the map calls Coast Range, 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 |
|---|---|---|---|---|
| Coast Range | Northern Coast Range is marine sedimentary rocks and Tertiary mafic volcanic rocks. Southern Coast Range is Tertiary estuarine and marine sedimentary rocks, feldspathic and micaceous. | Low | 7 | 97.8% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Tillamook County beside the ground around it
Across Oregon 62.3% of the land is rated moderate; none of Tillamook County's is. Of the 6 counties that border it, 5 have more moderate-potential ground, Columbia County the most at 91.6%.
The map rates the ground, not the air in any home.
Local help
Tillamook County, Local resources
Radon testing and mitigation in Tillamook 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
Tillamook County, Questions
Questions about radon in Tillamook County
Are radon levels high in Tillamook County?
In 2023, 9.1% of the radon tests reported to CDC for Tillamook County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Of 19 Oregon counties with 30 or more tests for the same period, 4 reported a higher share; pooled, the state comes to 16.3%.
Which counties border Tillamook County?
Tillamook County borders 6 counties: Yamhill County, Washington County, Polk County, Clatsop County, Lincoln County and Columbia County.
Products
Tillamook County, Products
Testing a home in Tillamook County
In Tillamook County, 19.8% of 126 tests reported to CDC in 2021 reached 4 pCi/L, against 16.3% 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 Tillamook County.
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
MonitorAranet
Radon One battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
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
Tillamook County, Bordering counties
Counties bordering Tillamook County
Calculated by Radon411- Radon levels in Clatsop CountyEPA zone 2
30.3%at or above 4 pCi/L
Median 1.9 pCi/L · 33 tests · 10.5 points above Tillamook County
- Radon levels in Washington CountyEPA zone 2
15.8%at or above 4 pCi/L
Median 1.1 pCi/L · 539 tests · 4.0 points below Tillamook County
- Radon levels in Yamhill CountyEPA zone 2
15.5%at or above 4 pCi/L
Median 1.3 pCi/L · 84 tests · 4.3 points below Tillamook County
- Radon levels in Columbia CountyEPA zone 2
15.2%at or above 4 pCi/L
Median 1.8 pCi/L · 33 tests · 4.6 points below Tillamook County
- Radon levels in Polk CountyEPA zone 3
15.0%at or above 4 pCi/L
Median 1.4 pCi/L · 100 tests · 4.8 points below Tillamook County
- Radon levels in Lincoln CountyEPA zone 3
9.4%at or above 4 pCi/L
Median 0.7 pCi/L · 32 tests · 10.4 points below Tillamook County
Tillamook County, Cities and towns
Cities and towns in Tillamook County
Tillamook County's population has barely moved since 2020: 27,384 residents on July 1, 2025 against 27,456 then, by the Census Bureau's estimates. That works out to 25 people per square mile of land. No town dominates: Tillamook, the largest, has 5,162 residents, 18.9% of the total. Together its 7 incorporated places hold 37.1% of those residents; the other 62.9% live outside any of them. Testing is reported here more often than across the state: CDC's 126 reported tests for 2021 come to 4.6 for every 1,000 residents (2025 estimate), against 1.0 for Oregon.
From Tillamook to Nehalem, CDC publishes no figure by town: each reads Tillamook County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Tillamook | 5,162 | −0.9% | 18.9% |
| Rockaway Beach | 1,455 | −0.1% | 5.3% |
| Bay City | 1,388 | +0.1% | 5.1% |
| Garibaldi | 816 | −0.6% | 3.0% |
| Manzanita | 648 | +6.6% | 2.4% |
| Wheeler | 426 | −0.9% | 1.6% |
| Nehalem | 272 | −0.7% | 1.0% |
7 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).
Tillamook County, Homes
Homes in Tillamook County
Of Tillamook County's 19,093 homes, 75% are detached houses, against 63% across Oregon; 12% are mobile homes. Half of its homes were built before 1981, close to Oregon's 1980: 25% date from before 1960 and 24% from 2000 or later. 73% 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 | Tillamook County | Oregon |
|---|---|---|
| Housing units | 19,093 | 1,838,631 |
| Detached houses | 75% | 63% |
| In buildings of 5 or more | 3% | 17% |
| Mobile homes | 12% | 8% |
| Built before 1960 | 25% | 23% |
| Built since 2000 | 24% | 24% |
| Middle year built | 1981 | 1980 |
| Owner-occupied | 73% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.