Smoke and Air Quality Update: Pacific Northwest Sees Improvement as Cooler Air Arrives

After weeks of persistent smoke and degraded air quality across Oregon and Washington, forecasters and air quality agencies are reporting a meaningful improvement as cooler temperatures, higher humidity, and scattered showers arrive across the region. The change offers welcome relief to communities that have spent much of the summer under smoke advisories and air quality alerts tied to the historic 2026 wildfire season.

Oregon Air Quality Status

The Oregon Department of Environmental Quality (DEQ) issued a smoke advisory earlier this week for portions of northern Crook, Jefferson, and southern Wasco counties, driven by multiple active wildfires in Oregon and Washington. That advisory was extended through approximately Wednesday, September 2, with Deschutes County transitioning to an intermittent smoke advisory by Tuesday evening.

A broader air quality advisory from early September cautioned that "wildfires burning in the region combined with forecasted conditions will cause air quality to reach unhealthy levels at times through noon Wednesday" — a forecast that has largely resolved as cleaner air has pushed into the region.

As of September 5, Portland's air quality index has returned to the Good category according to IQAir data, a notable improvement from the unhealthy and very unhealthy readings recorded throughout August. Central Oregon communities including Bend have also seen marked improvement, though smoke from residual large fires may still cause intermittent moderate readings on calm, stagnant mornings.

Washington Air Quality

Washington communities — particularly those in the Okanogan, Chelan, and Wenatchee regions downwind of multiple large active fires — have dealt with some of the worst air quality in the state this season. As precipitation and onshore flow increase this weekend, air quality monitoring stations in those areas are expected to show improvement, though smoke from ongoing fires may continue to produce localized degraded conditions, especially at night and in early morning hours when temperature inversions trap smoke near the ground.

Protecting Your Health

Health officials remind residents in smoke-affected areas to:

Check AirNow.gov or the Oregon DEQ smoke advisory page (oregonsmoke.org) for current conditions before heading outdoors
Use HEPA air purifiers indoors when AQI exceeds 100 (Unhealthy for Sensitive Groups)
Wear a properly fitted N95 or KN95/FFP2 respirator mask if outdoor activity is necessary during elevated smoke events — cloth masks and surgical masks do not filter fine particulate matter effectively
Keep windows and doors closed and recirculate vehicle air conditioning during smoke events
Create a clean air room in your home by sealing gaps and running a HEPA purifier continuously
Sensitive populations — including children, elderly individuals, pregnant women, and those with asthma, COPD, or heart disease — should minimize outdoor exposure whenever AQI exceeds 50 (Good/Moderate boundary)

Wildfire Smoke Health Risks

Wildfire smoke contains fine particulate matter (PM2.5), carbon monoxide, and hundreds of chemical compounds from burning vegetation and, when structures burn, synthetic materials. Prolonged or repeated exposure to smoke-level PM2.5 concentrations has been linked to increased rates of respiratory illness, cardiovascular events, and — in high-exposure populations — long-term lung function decline.

Oregon's 2026 wildfire season is the worst on record, and the cumulative smoke exposure burden on communities across the state has prompted public health discussions about chronic smoke exposure that go well beyond single-event advisories.

Resources

Current air quality data and smoke advisories are available at: