As the 2026 wildfire season draws to a close, the Washington State Department of Ecology has posted a comprehensive air quality review documenting the smoke burden that communities across the state endured this summer and fall. The picture is stark: most parts of Washington experienced unhealthy air quality at some point during the 2026 season, and some communities in north-central Washington saw weeks of hazardous conditions.

Chelan and Okanogan: Ground Zero for Smoke

It was an especially smoky year for Chelan and Okanogan counties, home to the Little Giant and Sinlahekin fires respectively. Air quality monitoring stations in the Wenatchee and Okanogan valleys repeatedly recorded PM2.5 concentrations in the "Very Unhealthy" and "Hazardous" categories — the two highest tiers of the Air Quality Index — during peak fire activity in August and September.

Several counties in Northeastern Washington, near the Idaho border and the Colville National Forest, also experienced prolonged periods of unhealthy air as smoke from fires across the region pooled in valleys and drifted on shifting winds.

What the Data Shows

Washington Ecology's review found that wildfire smoke drove most of the significant air quality events recorded statewide in 2026. The agency tracks air quality through a network of monitoring stations and satellite-derived smoke density products.

  • Days with AQI above 150 ("Unhealthy") in Chelan County exceeded historical averages by a significant margin
  • The Wenatchee area saw periods where air quality was worse than at any time since the 2020 fire season, which was itself a record year for smoke in the Pacific Northwest
  • Even western Washington communities, protected by the Cascade Range from most fire smoke, experienced multiple days of degraded air quality as large smoke columns pushed west during high-pressure events

Health Impacts and Vulnerable Populations

Public health officials in Chelan, Douglas, and Okanogan counties issued repeated smoke advisories throughout the season, urging residents with respiratory conditions, heart disease, the elderly, children, and pregnant women to remain indoors during the worst air quality events. Air filtration units were distributed at community centers in several affected communities.

Looking Ahead to 2027

The Ecology review is expected to inform planning for the 2027 fire season, including decisions about air monitoring network expansion and public communication strategies. State officials have also pointed to the record 2026 season as justification for increased investment in prescribed fire — which, while generating short-term smoke, can dramatically reduce the intensity and duration of wildfire-driven smoke events in the future.

Residents can access Washington Ecology's real-time air quality data and smoke forecasts year-round at ecology.wa.gov.