Is the air quality good in the western US?
Since late July 2026, air quality across a broad area of the western United States has been affected by dense smoke from nearby active wildfires, with PM2.5 as the dominant pollutant (1).
As of August 5, by 9:30 PM (local time, GMT-7), many urban centers have recorded AQI readings between 100 and 400, reaching unhealthy to hazardous levels and prompting health warnings (2).
Residents are advised to limit outdoor activity, keep windows and doors sealed, wear a mask if going outside is unavoidable, and run air purifiers indoors.
Air quality map of western US, as of 9:30 PM (GMT-7) on August 5, 2026. Source: IQAir.
Which cities are affected by bad air quality in the western US?
As of August 5, 2026, some of the most severely impacted cities include:
- Idaho: McCall, New Meadows, Rockford Bay, Weiser, Worley
- Oregon: Albany, Coburg, Eugene, Marion, Molalla, Mount Hood, Odell, Portland, Salem, Santa Clara, Springfield
- Washington: Barstow, Brewster, Chelan, Entiat, Kettle Falls, Leavenworth, Seattle, Twisp, Winthrop
Air quality conditions can change rapidly throughout the day. For a complete, real-time overview of pollution levels, see the United States air quality map.
Portland and Seattle ranked among the world's most polluted major cities as of 9:30 PM (GMT-7) on August 5, 2026. Source: IQAir.
When will the air quality improve in the western US?
Air quality is expected to remain poor through the rest of the week as wildfire smoke continues to linger. Light winds and stable weather conditions are expected to keep smoke trapped near the ground, delaying significant improvement (3).
What is causing poor air quality in the western US?
Poor air quality is being caused by smoke from multiple large wildfires burning across eastern Washington, northern Idaho, and surrounding areas. Extremely dry conditions are fueling fire activity and allowing dense smoke to spread into nearby communities (4).
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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.
- 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.
- Run a high-performance air purifier to filter particles, gases, and other pollutants.
