Smoke from a rash of Northwest wildfires is forecast to pour into western Washington and Oregon, leading to unhealthy air quality in Seattle, Portland and other cities.
Here’s where the fires are burning
The most numerous large wildfires right now are burning in the eastern two-thirds of Oregon and Washington.
Three of those burning in the Spokane, Washington, metro area destroyed hundreds of homes and businesses. Thirty large fires are burning in central and eastern Oregon.
Other large fires are burning in Idaho, Montana and Utah, among other western states.
(MORE: The Weather Company Labs: active wildfires and fire weather tracker)
Where the smoke will go
Ground-level wildfire smoke over the past week or so has largely been confined to the interior Northwest closest to the fires. But that’s changing.
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The typical west-to-east onshore winds in the Pacific Northwest are turning around. Over the next few days, offshore winds will blow from the east or northeast.
Winds from that direction will pull increasing ground-level smoke into western Oregon and western Washington.
That includes the Interstate 5 corridor, including Seattle, Tacoma and Olympia, as well as Oregon’s Willamette Valley, including Portland, Salem, Corvallis and Eugene.
Ground smoke will also continue in Boise, and could flow as far south as Salt Lake City, according to some computer models.
This smoke could linger at least into Wednesday, if not a bit longer.
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Some record heat, too?
If that wasn’t enough, the same pattern that’s drawing the wildfire smoke westward is also turning up the heat west of the Cascades.
Daytime highs may approach 90 degrees in Seattle and upper 90s in Portland, though if the smoke is dense enough, that could knock a few degrees off those daytime highs.
Is there any relief?
Summer is the Pacific Northwest’s dry season, so it’s hard to get the kind of soaking rain and mountain snow you’d see in, say, November.
There is a little better news in the forecast, however. It will gradually trend cooler in the Northwest this weekend.
Next week, monsoon thunderstorms may extend well into the northern Rockies.
That’s a mixed blessing, though. While rain is sorely needed, even light rain over areas just burned could lead to dangerous flash flooding and muddy debris flows. And some areas may see only lightning and winds, not rain.
What you need to know to stay safe
Wildfire smoke is hazardous to breathe for several reasons.
It contains microscopic particulate matter much smaller than the width of a human hair that can lodge deep into the lungs and then enter your bloodstream.
It can lead to short-term effects, such as coughing, shortness of breath, a scratchy throat, runny nose and burning eyes.
Prolonged exposure to dense smoke can increase the risk of chronic lung issues and increase inflammation that could lead to heart attacks and strokes.
(MORE: How air pollution affects you)
Check your air quality forecast before heading outside.
You can do that on The Weather Channel app by going to your local forecast, then tapping the “Breathing” button. Or, from your local forecast page on weather.com, click on the “Air Quality” button at the top.
The index is color-coded from green (good) to maroon (hazardous).
If your air quality forecast is:
- At least code orange: More sensitive groups such as those with respiratory or heart conditions, the elderly, children and those pregnant should avoid staying outside more than necessary.
- Code red, purple or maroon: Everyone should limit their time outdoors. Consider exercising indoors and if you need to walk your pet outside, do so as briefly as possible.
(MORE: Wildfire smoke myths)
Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. Extreme and bizarre weather are his favorite topics. Reach out to him on Bluesky, X (formerly Twitter) and Facebook.
