Washington Air Quality Forecast: How Long Will The Smoke Last?

SEATTLE, WA — Western Washington will be plagued with smoke from wildfires burning in Oregon and California through at least the weekend, with the potential for especially thick clouds Friday night into Saturday morning, according to the latest forecasts.

The "super-massive body of smoke" began creeping into the state Thursday, pouring over Western Washington and into British Columbia Friday, with tendrils extending across the Columbia Basin and soon out to Spokane.

Latest: Smoke Forecast: Diminished Chances For Cleaner Air In Washington

By late Friday afternoon, air quality had degraded to the hazardous range around Seattle, Bellevue, Tacoma and Olympia, and registered as "unhealthy" or "very unhealthy" at minimum throughout Puget Sound.

That pattern remained largely intact Saturday morning, with readings on the high side of the "very unhealthy" range in cities up and down Interstate 5, and showing as hazardous on the Olympic Peninsula and along the coast.

Unfortunately, forecasters expect air quality will remain diminished for most of the weekend, as a low-level onshore flow pulls in more smoke. Saturday could be worse than Friday in some areas, especially in the morning, after smoke thickens overnight. In Seattle, Mayor Jenny Durkan ordered all city parks, beaches, boat launches and golf courses closed through Sunday. An air quality alert is active until at least Monday morning.

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According to the National Weather Service, some limited relief may come as conditions begin to gradually improve Sunday, but health impacts will likely remain. Due in part to the smoke, afternoon highs will be lower than recent days, from the low 60s to low 70s on Saturday and Sunday.

The real change-up appears Monday, forecasters said, when a frontal system will bring a welcome chance for rain showers, spreading from west to east, and vastly improve air quality region-wide.

Live updates on air quality can be found via the Puget Sound Clean Air Agency, AirNow and Department of Ecology websites, along with the daily smoke forecast. New information will continue to be posted on the Washington Smoke Blog.

Until conditions improve substantially, even those in top health are encouraged to avoid outdoor activities and protect themselves from harmful smoke. According to health officials, many of the same groups that are especially at-risk for COVID-19 complications also face heightened health effects from smoke.

Generally, the state Department of Health recommends:

• Stay updated on current and forecasted air quality.
• Avoid physical exertion outdoors if smoke is in the air.
• If you have asthma or other lung diseases, make sure you follow your doctor's directions about taking your medicines and follow your asthma management plan. Call your health care provider if your symptoms worsen.
• Stay indoors and keep indoor air as clean as possible.
  • Keep windows and doors closed. Track the air quality and open your windows for fresh air when the air quality improves. Pay attention to the heat indoors and follow guidance in the section below if it's too hot.
  • Improve the filtration in your home.
  • Run an air conditioner, set it to re-circulate and close the fresh-air intake. Make sure to change the filter as the manufacturer recommends. It may get dirty faster when smoke is prolonged.
  • Don’t add to indoor pollution.
    • Avoid using candles, incense, sprays, fireplaces, or gas stoves.
    • Don’t broil or fry food or smoke cigarettes indoors.
    • Avoid vacuuming unless your vacuum has a HEPA filter, because vacuuming stirs up particles already inside your home.
  • Consider leaving the area if the air quality is poor and it's not possible to keep indoor air clean, especially if you or those you are caring for are having health problems or are in a sensitive group. See section above for who is especially sensitive to smoke.

Learn more about protecting your family from wildfire smoke on the Department of Health website.