Radon levels in Portland, Oregon
ModerateEPA Zone 2Predicted long-term basement average of 2.0 pCi/L (model estimate) across the 27 modeled ZIP codes in Portland - close to the US average of 1.8, about 1.2× the Oregon average of 1.7. Ranked #1 of 13 Oregon cities on this site. Most of the city lies in Multnomah County (its ZIPs also reach into 1 other county).
Test Portland, OR - the EPA says "consider fixing" in this range
The predicted basement average here is 2.0 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.
Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.
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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.
2.0 ± 0.08
pCi/L predicted basement mean (model SD)
1.1 ± 0.09
pCi/L predicted upstairs (above-ground) mean
1.0-2.6
range of ZIP-level basement predictions in the city
0%
of Portland ZIPs predicted ≥ 4 pCi/L (59% ≥ 2)
What this means for Portland
The typical Portland home is predicted in the 2-4 pCi/L band. The EPA's guidance for this range is to consider fixing, because there is no known safe level and a meaningful minority of homes in a moderate area will test above 4.
The city figure is not a separate estimate: it is the mean of the model's ZIP-code predictions, weighted by the share of the city's land in each ZIP (Census 2020 ZCTA-to-place relationship file). The 1993 EPA zone (2) for Multnomah and the 2001-2021 model agree here.
Comparable Oregon cities: Salem (1.8), Albany (1.8), Bend (1.7), Medford (1.7).
ZIP codes in Portland
ZIPs that overlap the city, largest share of its land first. Predicted basement and upstairs means are model estimates; ZIPs the model does not cover show a dash.
| ZIP | Share of city | Basement | Upstairs | Grade |
|---|---|---|---|---|
| 97203 | 8% | 2.0 ± 0.07 | 1.0 | Low |
| 97219 | 8% | 1.4 ± 0.07 | 0.8 | Low |
| 97217 | 7% | 2.1 ± 0.08 | 1.0 | Moderate |
| 97210 | 6% | 1.7 ± 0.09 | 0.8 | Low |
| 97220 | 6% | 2.6 ± 0.07 | 1.3 | Moderate |
| 97211 | 5% | 2.4 ± 0.08 | 1.0 | Moderate |
| 97230 | 5% | 2.4 ± 0.09 | 1.5 | Moderate |
| 97236 | 5% | 2.2 ± 0.09 | 1.1 | Moderate |
| 97218 | 5% | 2.5 ± 0.09 | 1.1 | Moderate |
| 97202 | 5% | 2.1 ± 0.07 | 1.0 | Moderate |
| 97206 | 5% | 2.3 ± 0.07 | 1.3 | Moderate |
| 97266 | 5% | 2.1 ± 0.06 | 1.2 | Moderate |
| 97231 | 3% | 1.5 ± 0.09 | 1.0 | Low |
| 97213 | 3% | 2.6 ± 0.09 | 1.4 | Moderate |
| 97229 | 3% | 1.0 ± 0.08 | 0.5 | Low |
| 97221 | 3% | 1.3 ± 0.09 | 0.8 | Low |
| 97239 | 3% | 1.3 ± 0.12 | 0.8 | Low |
| 97233 | 2% | 2.1 ± 0.07 | 1.1 | Moderate |
| 97214 | 2% | 2.1 ± 0.07 | 1.0 | Moderate |
| 97212 | 2% | 2.2 ± 0.07 | 1.2 | Moderate |
| 97216 | 2% | 2.3 ± 0.09 | 1.2 | Moderate |
| 97215 | 2% | 2.1 ± 0.07 | 1.0 | Moderate |
| 97201 | 1% | 1.5 ± 0.08 | 0.8 | Low |
| 97232 | 1% | 2.2 ± 0.06 | 1.0 | Moderate |
| 97227 | 1% | 1.9 ± 0.06 | 0.9 | Low |
| 97209 | 1% | 1.6 ± 0.07 | 0.8 | Low |
| 97205 | 1% | 1.2 ± 0.10 | 0.8 | Low |
| 97204 | <1% | — | — | no model |
| 97208 | <1% | — | — | no model |
| 97258 | <1% | — | — | no model |
Testing help in Oregon
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. EPA state radon contacts page. If a test comes back at 4 pCi/L or higher, mitigation typically costs $800-$2,500 installed; use EPA find-a-professional and read the mitigation guide.
Portland radon questions
- Is radon high in Portland, Oregon?
- Moderate. Averaging the model's ZIP-code predictions across Portland (weighted by how much of the city each ZIP covers) gives a long-term basement mean of 2.0 pCi/L - close to the US average of 1.8 and about 1.2× the Oregon average of 1.7. That is in the 2-4 pCi/L range where the EPA says to consider fixing. Portland ranks 1 of 13 Oregon cities on this site.
- Which Portland ZIP codes have the highest radon?
- Predictions for the 27 modeled ZIP codes in Portland range from 1.0 to 2.6 pCi/L in the basement. 0% of them are predicted at or above 4 pCi/L and 59% at or above 2. That spread is why the ZIP table below matters more than the city-wide number.
- Should I test for radon in Portland?
- Yes, soon. With a predicted basement average of 2.0 pCi/L, a meaningful share of Portland homes will test above the 4 pCi/L action level. Start with a short-term kit; if it reads 2 or higher, confirm with a long-term test or a continuous monitor before paying for mitigation.
- What does EPA Radon Zone 2 mean for Portland?
- Portland sits mainly in Multnomah County, which the EPA classifies as Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and covers whole counties. The 2001-2021 model agrees with the zone for the city. Neither replaces a test of your own home.
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