Weeks of widespread wildfire activity across the Pacific Northwest have produced a persistent smoke layer blanketing much of Oregon, Washington, and Idaho. State environmental agencies have issued air quality advisories covering dozens of counties, and public health officials are urging vulnerable populations to limit outdoor exposure.

The Worst Air Quality Event of the Season

The most severe smoke event of the 2026 season occurred on August 5, when the air quality index (AQI) in Leavenworth, Washington, recorded a reading above 849 — more than seven times the traditional maximum index value of 500. The extreme reading was driven primarily by smoke from the Little Giant Fire burning approximately 30 miles away in the Cascade foothills.

Under Washington Department of Labor and Industries safety rules, transit services in the Leavenworth area were suspended when AQI values exceeded 849. Governor Ferguson declared a statewide public health emergency on August 7, citing the unprecedented air quality impacts from wildfire smoke across the state.

Current Advisories by State

Oregon

Oregon DEQ has issued air quality advisories affecting a broad swath of the state. Counties currently under advisories or recent alerts include:

  • Baker County — Smoke from the McCully Fire and nearby incidents
  • Umatilla County — Transported smoke from multiple fires
  • Clackamas County — Intermittent smoke from the Austin Fire
  • Deschutes, Marion, Multnomah, and southern Wasco counties — Intermittent smoke, with conditions changing rapidly depending on wind direction

Real-time AQI readings across Oregon are available at oregon.gov/deq/aq/Pages/AQI.aspx.

Washington

Multiple air quality management districts across eastern and central Washington continue to monitor smoke from active fires including the Avery Park Fire, Sinlahehkin Fire, and residual smoke from the Spokane Complex. AQI readings across eastern Washington have fluctuated between the Unhealthy and Very Unhealthy categories this week.

Idaho

With 44 active wildfires burning across 20 Idaho counties as of August 24, smoke impacts are widespread in the northern and central parts of the state. The Clearwater region has been particularly affected, with the Moose Mountain Fire on the Nez Perce-Clearwater National Forest contributing smoke to the Kamiah and Orofino areas.

How to Protect Yourself

Public health agencies recommend the following steps when smoke advisories are in effect:

  • Stay indoors with windows and doors closed; use air conditioning on recirculate mode if available
  • Use HEPA air purifiers to reduce indoor particulate levels
  • Wear N95 or KN95 masks if you must be outdoors; surgical masks and cloth coverings do not filter fine particles effectively
  • Avoid strenuous outdoor activity — exercise increases the volume of air (and smoke particles) inhaled
  • Check on neighbors — elderly individuals, children, pregnant women, and those with heart or lung conditions are most vulnerable
  • Create a clean air room in your home by keeping one room as smoke-free as possible

Monitoring Resources

The following tools provide real-time air quality data for Pacific Northwest communities:

  • AirNow.gov — Federal air quality monitoring network with current AQI by ZIP code
  • PurpleAir.com — Citizen science sensor network with hyperlocal readings
  • Oregon DEQ: oregon.gov/deq/aq
  • Washington Ecology: ecology.wa.gov/Air-Climate
  • Idaho DEQ: deq.idaho.gov/air

Smoke conditions can change rapidly as wind patterns shift. Health officials recommend checking air quality before planning outdoor activities, even on days that appear clearer, as fine particle levels can be unhealthy even when smoke is not visually apparent.