SmogRank / World / United States / Oregon / September 2025
Most polluted cities in Oregon, United States, September 2025
43 cities in Oregon, United States ranked by their average PM2.5 over the 30 days. Worst: Grants Pass at 17.5 µg/m³, #268 of 3,052 cities in the world. Cleanest: Newport at 1.9. A city needs measurements on 70% of the days to be ranked.
Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.
- 1Grants Pass 13%
- 2Ashland 7%
- 3Talent 3%
- 4Medford 3%
- 5Prineville 3%
- 6Hermiston 0%
- 7Madras 0%
- 8Pendleton 0%
- 9La Grande 0%
- 10Ontario 0%
- 11Baker City 0%
- 12Cottage Grove 0%
- 13The Dalles 0%
- 14Bend 0%
- 15Redmond 0%
- 16Eugene 0%
- 16Green 0%
- 18Albany 0%
- 19Stayton 0%
- 19Tigard 0%
- 21Canby 0%
- 22Gresham 0%
- 22Portland 0%
- 22Roseburg 0%
- 22Salem 0%
- 22Sweet Home 0%
- 27Altamont 0%
- 28Beaverton 0%
- 28Oregon City 0%
- 28Silverton 0%
- 31Hillsboro 0%
- 31Milwaukie 0%
- 33Florence 0%
- 34Hood River 0%
- 35Brookings 0%
- 35Woodburn 0%
- 37Corvallis 0%
- 37North Portland 0%
- 39Dallas 0%
- 40McMinnville 0%
- 41Coos Bay 0%
- 42Forest Grove 0%
- 43Newport 0%
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
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SmogRank, most polluted cities in Oregon, United States, PM2.5, September 2025, smogrank.com/us/region/oregon/history/2025-09 (accessed 6 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.