Smoke and Air Quality: What Pacific Northwest Residents Need to Know This Fall

Wildfire smoke has been an unwelcome companion for Pacific Northwest residents throughout the 2026 season, and the combination of still-active fires, incoming prescribed burns, and a warming weather pattern means air quality concerns will continue into fall. Whether you are in eastern Washington near the Little Giant or Sinlahekin fire footprints, in the Cascades corridor near the Sisi or Three Queens fires, or in western Oregon where smoke can pool in valleys, understanding your risk and your options is essential.

Current Air Quality Situation

As of early October, the most active smoke sources in the Pacific Northwest are the five large fires still burning in Washington state. The Sisi Fire (10 miles northwest of Stehekin) and the Three Queens Fire (6 miles east of Snoqualmie Pass) are both in remote Cascade terrain, but smoke from these fires can settle into valleys and communities downwind depending on wind patterns and temperature inversions.

The onset of the fall prescribed burn season — with the BLM and U.S. Wildland Fire Service announcing operations across Oregon and Washington this week — will add additional smoke events, particularly in the evenings when smoke from burns tends to settle into lower elevations. The Deschutes National Forest near Crescent has already been conducting burns.

Understanding the AQI

The Air Quality Index (AQI) is the standard tool for communicating how clean or polluted the air is. Here is what the numbers mean for wildfire smoke (driven primarily by fine particulate matter, PM2.5):

0–50 (Good): Air quality is satisfactory, and air pollution poses little or no risk.
51–100 (Moderate): Unusually sensitive individuals may experience minor symptoms. Most people are not affected.
101–150 (Unhealthy for Sensitive Groups): Children, elderly, and those with heart or lung conditions should limit prolonged outdoor exertion.
151–200 (Unhealthy): Everyone may begin to experience health effects. Sensitive groups should avoid prolonged outdoor activity.
201–300 (Very Unhealthy): Health warnings apply to the general population. Avoid prolonged outdoor activity.
301+ (Hazardous): Everyone should avoid all outdoor exertion. Health emergency conditions.

Protecting Yourself from Smoke

Monitor air quality at AirNow.gov or the EPA’s AirNow app before going outdoors
Keep windows and doors closed when outdoor air quality is Unhealthy or worse
Use a HEPA air purifier indoors if available
N95 or P100 respirators provide meaningful protection if you must go outside during poor air quality events — cloth masks and surgical masks do not filter PM2.5 effectively
Avoid vigorous outdoor exercise when air quality is in the Unhealthy for Sensitive Groups range or worse
Consult your doctor if you have asthma, COPD, heart disease, or other conditions that may be worsened by smoke exposure

Resources for Monitoring

AirNow.gov — Real-time AQI maps for the Pacific Northwest
Fire and Smoke Map — AirNow’s wildfire-specific smoke tracking tool
Oregon DEQ Air Quality: oregonair.deq.state.or.us
Washington State Department of Ecology Air Monitoring: enviwa.ecology.wa.gov
Idaho DEQ Air Quality: deq.idaho.gov/air

When Prescribed Burns Are Planned

Agency guidelines require that prescribed burns be conducted only when weather, fuel conditions, and air quality are within specified parameters. However, smoke from managed burns can still affect nearby communities, particularly in evenings when inversions trap smoke at lower elevations. Agencies post burn notices in advance; check with your local BLM or Forest Service district for upcoming activity in your area.