Smoke from the Pacific Northwest’s historic wildfire siege has blanketed the region in a thick, acrid haze, driving air quality to hazardous levels across Oregon, Washington, and Idaho. At the height of the smoke event in early August, Portland’s Air Quality Index briefly ranked among the worst of any major city on the planet — a grim milestone for a region still weeks from the traditional end of fire season.

Air quality advisories remain in effect for most of the Pacific Northwest. Near the most active fires, AQI readings have climbed well into the “Very Unhealthy” and “Hazardous” categories — levels at which outdoor exposure poses serious health risks even for healthy adults.

Major Cities Affected

The smoke has not been limited to communities immediately adjacent to fires. Major metropolitan areas across the region have experienced significant air quality degradation this week:

  • Portland, Oregon: Briefly ranked among the worst air quality of any major world city on August 4, 2026
  • Seattle, Washington: Multiple consecutive days of Unhealthy to Very Unhealthy AQI readings
  • Boise, Idaho: Poor air quality forecast throughout the week
  • Spokane, Washington: Eastern Washington reached “Very Unhealthy” levels Monday morning, August 3

The smoke even traveled hundreds of miles south, prompting the Bay Area Air Quality Management District to extend an advisory for Bay Area residents through Thursday, August 6 — attributing the smoke directly to Pacific Northwest fires.

A Shifting Pattern

An incoming Pacific air pattern is expected to shift smoke movement through the latter part of this week, potentially bringing some relief to coastal communities in Washington and Oregon while pushing denser smoke further inland toward the Cascades and Columbia Basin. The coast of Washington and Oregon may see some cooling and cleaner air, while interior valleys could experience worsened conditions temporarily.

Protecting Yourself

Public health officials across Oregon, Washington, and Idaho are urging residents to take smoke exposure seriously. Key protective actions include:

  • Stay indoors with windows and doors closed when AQI is Unhealthy or above (101+)
  • Use a properly fitted N95 or KN95 mask if you must go outside
  • Run HVAC systems on recirculate with MERV-13 or better filters
  • Consider a DIY Corsi-Rosenthal air filter (box fan + furnace filters) for under $65
  • Avoid all strenuous outdoor exercise on smoky days
  • Check real-time conditions at fire.airnow.gov for hourly AQI updates and health recommendations

Sensitive populations — including children, the elderly, pregnant women, and anyone with cardiovascular or respiratory conditions — should follow precautions even at Unhealthy for Sensitive Groups levels (AQI 101–150).

When to Seek Medical Help

Seek immediate medical attention if you experience chest pain or tightness, difficulty breathing, shortness of breath, or if your symptoms worsen rapidly. These can be signs of serious smoke-related health impacts requiring prompt care.