Is the air quality good in Portland?
As of August 31, 2026, at 11:00 PM (local time), air quality in Portland, Oregon, is poor, with an AQI of 184, which falls within the "unhealthy" range.
Conditions rapidly deteriorated from moderate to unhealthy late Monday evening as wildfire smoke entered western Oregon and southwest Washington (1).
These conditions can affect everyone, with children, older adults, pregnant people, and those with respiratory or cardiovascular conditions facing greater risks.
Air quality is dynamic and, like the weather, can change frequently. Portland ranked as the second most polluted major city in the world on Monday night.
Click here for a real-time air quality map of Portland.
While the air quality conditions today are poor, it is important to note that the average PM2.5 concentration in 2025 for Portland was 6 µg/m³. This corresponds to an AQI of 25, which falls into the “good” category and was 1.2 times the WHO annual guideline of 5 µg/m³.
Portland, Oregon, ranked as the second most polluted major city on August 31, 2026, at 11:00 PM (local time). Source: IQAir.
When will air quality improve in Portland?
Air quality is forecast to improve into the moderate range on Tuesday as southwesterly winds push smoke toward the northeast.
Hourly air quality forecast for Portland, Oregon, on August 31, 2026. Source: IQAir.
Rain is expected to arrive by Wednesday, helping clear the remaining smoke and reduce wildfire activity. The rain may continue through Friday, supporting further improvement (2).
Air quality map of Portland, Oregon, on August 31, 2026. Source: IQAir.
What is causing poor air quality in Portland?
Portland’s poor air quality is caused by smoke from wildfires burning in Oregon, particularly the Austin Fire, the Narrows Fire, and the weakening Grasshopper Fire. Easterly winds carried the smoke into the Willamette Valley and north toward Portland (3).
The Austin Fire, burning southeast of Estacada in the Mt. Hood National Forest, remains a significant source of smoke (4).
How can I protect myself from poor air quality?
- Get a free air quality app for real-time air quality alerts and forecasts.
- Shut doors and windows and set the HVAC to recirculate mode.
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Contribute to your community’s outdoor air quality data.
- Stay indoors when air quality is poor; if you do need to go outdoors, wear a KN95/FFP2 mask.
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Run a high-performance air purifier to filter particles, gases, and other pollutants.
