Radon levels in Oregon: Low
The model predicts a population-weighted basement average of 1.7 pCi/L (model estimate) across Oregon's 36 counties - close to the US average of 1.8 pCi/L. Above-ground floors average 0.9 pCi/L.
Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.
0 / 36
EPA Zone 1 counties (0%)
21 / 15
Zone 2 / Zone 3 counties
0
counties predicted ≥ 4 pCi/L
0%
of ZIP codes predicted ≥ 4 pCi/L
Test Oregon once anyway - radon varies house to house
The predicted basement average here is 1.7 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.
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What the data says about radon in Oregon
0 of Oregon's 36 counties are EPA Zone 1 (0%), 21 are Zone 2 and 15 are Zone 3 on the EPA's county-level map. Zone 2 (predicted screening average of 2-4 pCi/L) is the most common designation. The zones were drawn once, from geology and the tests available in 1993, and the EPA itself notes that homes with elevated radon exist in all three zones.
Weighted by where people live, Oregon's predicted basement average is 1.7 pCi/L - close to the US average of 1.8 - which puts the state in the low range. Of the 36 counties with predictions, 0 are predicted at or above 4 pCi/L, 9 in the 2-4 band and 27 below 2. The highest predicted county is Union County at 2.5 pCi/L; the lowest is Douglas County at 1.4 - a 1.1 pCi/L spread that means a statewide average tells you little about any one county.
Nationally 4.2% of ZIPs are predicted at 4+ pCi/L and 48.7% at 2+; in Oregon it is 0% and 22.9% - below the national figures on both counts. No ZIP in the state is predicted above 4 on average - but averages hide individual homes, which is why the EPA still asks everyone to test.
Oregon counties by predicted radon
Sorted highest to lowest predicted basement average (model estimate). 36 counties.
| County | Predicted basement | Upstairs | Grade | EPA zone | ZIPs |
|---|---|---|---|---|---|
| Union County | 2.5 pCi/L | 1.0 | Moderate | EPA Zone 2 | 7 |
| Baker County | 2.3 pCi/L | 1.3 | Moderate | EPA Zone 2 | 8 |
| Wallowa County | 2.3 pCi/L | 1.3 | Moderate | EPA Zone 3 | 5 |
| Malheur County | 2.3 pCi/L | 1.3 | Moderate | EPA Zone 2 | 11 |
| Wheeler County | 2.2 pCi/L | 1.2 | Moderate | EPA Zone 2 | 3 |
| Grant County | 2.1 pCi/L | 1.2 | Moderate | EPA Zone 2 | 10 |
| Lake County | 2.0 pCi/L | 1.2 | Moderate | EPA Zone 2 | 7 |
| Gilliam County | 2.0 pCi/L | 1.1 | Moderate | EPA Zone 2 | 2 |
| Multnomah County | 2.0 pCi/L | 1.0 | Moderate | EPA Zone 2 | 31 |
| Klamath County | 2.0 pCi/L | 0.8 | Low | EPA Zone 2 | 13 |
| Harney County | 1.9 pCi/L | 1.0 | Low | EPA Zone 2 | 6 |
| Crook County | 1.9 pCi/L | 0.9 | Low | EPA Zone 2 | 3 |
| Sherman County | 1.9 pCi/L | 1.1 | Low | EPA Zone 2 | 5 |
| Jefferson County | 1.9 pCi/L | 0.9 | Low | EPA Zone 2 | 4 |
| Umatilla County | 1.8 pCi/L | 1.1 | Low | EPA Zone 2 | 11 |
| Marion County | 1.8 pCi/L | 1.1 | Low | EPA Zone 3 | 23 |
| Yamhill County | 1.8 pCi/L | 1.0 | Low | EPA Zone 2 | 11 |
| Jackson County | 1.8 pCi/L | 0.8 | Low | EPA Zone 3 | 15 |
| Morrow County | 1.7 pCi/L | 0.9 | Low | EPA Zone 2 | 5 |
| Linn County | 1.7 pCi/L | 1.0 | Low | EPA Zone 3 | 15 |
| Deschutes County | 1.7 pCi/L | 0.6 | Low | EPA Zone 3 | 7 |
| Hood River County | 1.7 pCi/L | 1.0 | Low | EPA Zone 2 | 3 |
| Benton County | 1.7 pCi/L | 1.1 | Low | EPA Zone 3 | 5 |
| Polk County | 1.7 pCi/L | 1.1 | Low | EPA Zone 3 | 6 |
| Wasco County | 1.7 pCi/L | 1.0 | Low | EPA Zone 2 | 8 |
| Columbia County | 1.6 pCi/L | 1.1 | Low | EPA Zone 2 | 8 |
| Josephine County | 1.6 pCi/L | 0.8 | Low | EPA Zone 3 | 10 |
| Clatsop County | 1.6 pCi/L | 1.0 | Low | EPA Zone 2 | 7 |
| Lane County | 1.6 pCi/L | 0.9 | Low | EPA Zone 3 | 35 |
| Clackamas County | 1.6 pCi/L | 0.9 | Low | EPA Zone 3 | 24 |
| Curry County | 1.5 pCi/L | 0.8 | Low | EPA Zone 3 | 6 |
| Coos County | 1.5 pCi/L | 0.8 | Low | EPA Zone 3 | 8 |
| Lincoln County | 1.5 pCi/L | 0.8 | Low | EPA Zone 3 | 15 |
| Tillamook County | 1.5 pCi/L | 0.9 | Low | EPA Zone 3 | 11 |
| Washington County | 1.4 pCi/L | 0.8 | Low | EPA Zone 2 | 21 |
| Douglas County | 1.4 pCi/L | 0.8 | Low | EPA Zone 3 | 24 |
Radon levels in Oregon cities
The 13 most-populous Oregon places among the 1,000 largest US cities (Census incorporated places and CDPs), by population. City figures are ZIP-land-weighted means of the model's ZIP predictions (model estimate).
| City | Population | Predicted basement | Upstairs | Grade | ZIPs ≥ 4 |
|---|---|---|---|---|---|
| Portland | 630,498 | 2.0 pCi/L | 1.1 | Moderate | 0% |
| Eugene | 177,899 | 1.6 pCi/L | 0.9 | Low | 0% |
| Salem | 177,432 | 1.8 pCi/L | 1.2 | Low | 0% |
| Gresham | 110,685 | 1.6 pCi/L | 0.8 | Low | 0% |
| Hillsboro | 107,730 | 1.4 pCi/L | 0.8 | Low | 0% |
| Bend | 104,557 | 1.7 pCi/L | 0.6 | Low | 0% |
| Beaverton | 96,945 | 1.5 pCi/L | 0.7 | Low | 0% |
| Medford | 85,098 | 1.7 pCi/L | 0.8 | Low | 0% |
| Corvallis | 61,087 | 1.7 pCi/L | 1.2 | Low | 0% |
| Springfield | 61,085 | 1.6 pCi/L | 0.9 | Low | 0% |
| Albany | 57,053 | 1.8 pCi/L | 1.0 | Low | 0% |
| Tigard | 55,590 | 1.3 pCi/L | 0.7 | Low | 0% |
| Aloha | 49,425 | 1.6 pCi/L | 0.8 | Low | 0% |
Highest-radon ZIP codes in Oregon
The 10 Oregon ZIP codes with the highest predicted basement average (model estimate), out of 393 modeled. A ZIP average is still an area figure - neighboring homes routinely test several pCi/L apart.
| ZIP | County | Predicted basement | Upstairs | Grade |
|---|---|---|---|---|
| 97850 | Union County | 2.6 pCi/L | 1.0 | Moderate |
| 97213 | Multnomah County | 2.6 pCi/L | 1.4 | Moderate |
| 97220 | Multnomah County | 2.6 pCi/L | 1.3 | Moderate |
| 97218 | Multnomah County | 2.5 pCi/L | 1.1 | Moderate |
| 97750 | Wheeler County | 2.5 pCi/L | 1.4 | Moderate |
| 97828 | Wallowa County | 2.5 pCi/L | 1.4 | Moderate |
| 97230 | Multnomah County | 2.4 pCi/L | 1.5 | Moderate |
| 97211 | Multnomah County | 2.4 pCi/L | 1.0 | Moderate |
| 97814 | Baker County | 2.4 pCi/L | 1.3 | Moderate |
| 97216 | Multnomah County | 2.3 pCi/L | 1.2 | Moderate |
Oregon radon questions
- Is radon high in Oregon?
- Oregon's population-weighted predicted basement average is 1.7 pCi/L, close to the US average of 1.8. 0 of its 36 modeled counties are predicted at or above the EPA action level of 4 pCi/L, 9 are in the 2-4 "consider fixing" range and 27 are below 2. 0% of Oregon ZIP codes are predicted at 4 or higher.
- Which Oregon county has the highest radon?
- Union County has the highest predicted basement average in Oregon at 2.5 pCi/L (EPA Zone 2). The lowest is Douglas County at 1.4 pCi/L. These are area figures; individual homes in any county can test far higher.
- How many EPA Zone 1 counties are in Oregon?
- 0 of Oregon's 36 counties (0%) are EPA Zone 1 (highest potential), 21 are Zone 2 and 15 are Zone 3. The EPA zone map dates from 1993; the predicted values on this page come from a 2001-2021 model built on millions of actual tests, so the two can disagree for a given county.
- Should I test for radon in Oregon?
- Yes. Even though Oregon's predicted average is below 2 pCi/L, the EPA recommends every home be tested - radon varies house to house, and 22.9% of Oregon ZIP codes are still predicted at 2 pCi/L or higher.
Oregon radon program
Oregon's radon program page is at www.oregon.gov and, when we checked it, offered a free short-term test kit for residents of higher-radon areas of Oregon. The EPA also keeps a directory of every state radon contact: EPA state radon contacts page. Then read how to test and what mitigation costs.