After a long summer of smoke and haze, air quality is improving significantly across much of the Pacific Northwest this week as a seasonal weather pattern brings rainfall and clearing conditions. However, some areas — particularly the Vancouver/Southwest Washington region — are still dealing with smoke from Oregon’s historic 2026 wildfire season.

Western Oregon and Washington Clearing

The National Interagency Fire Center’s latest weather briefing notes that more widespread rainfall is expected near and west of the Cascades in Oregon and Washington, with wetting rain also expected in northern Idaho and western Montana. Breezy westerly winds in the Columbia Basin are accompanied by higher relative humidity above 30%, which has helped significantly in reducing particulate matter concentrations across the region.

Air quality monitors across the Willamette Valley, Puget Sound, and the Oregon and Washington coasts are showing Good to Moderate readings as of September 28, a dramatic improvement from the Unhealthy and Very Unhealthy conditions that persisted through much of August and into September.

Southwest Washington Advisory Still Active

The Vancouver and Southwest Washington area has been under an Unhealthy air quality advisory related to wildfire smoke drifting north from Oregon’s active 2026 fire season. The advisory noted that the smoke was compounded by a separate ozone advisory issued simultaneously, creating a multi-pollutant air quality event for the region.

Residents in Clark, Cowlitz, and Skamania counties are advised to:

  • Limit prolonged outdoor exertion, particularly strenuous activity
  • Keep windows and doors closed when possible
  • Use air purifiers with HEPA filters indoors if available
  • Check AirNow.gov for real-time air quality index (AQI) readings before outdoor activities
  • Sensitive groups — including children, the elderly, and those with respiratory conditions — should avoid extended time outdoors

Eastern Oregon and Washington

The interior regions, which bore the brunt of smoke impacts during peak fire season, have also seen marked improvement. Eastern Washington communities near the Sinlahekin and Little Giant fire areas report that skies have largely cleared, a welcome development for communities that experienced near-continuous smoke for weeks during August and early September.

Minimum relative humidity values are lowest from 10–20% in areas from northern Nevada into central Montana — a region that remains more volatile from a fire weather perspective — but the Pacific Northwest’s own fire complexes are no longer significant smoke sources at the same scale as during peak season.

Resources for Monitoring

Pacific Northwest residents can track current air quality conditions at:

  • AirNow.gov — official EPA/agency air quality data
  • WA Ecology Air Quality — ecology.wa.gov/air
  • Oregon DEQ Air Quality — deq.oregon.gov/aq
  • PurpleAir — community sensor network with hyperlocal readings

As the fire season officially winds toward conclusion, air quality agencies expect continued improvement through October, barring any new significant fire starts in the region.