Editor’s note: This article was originally published August 3, 2017. It has been updated multiple times, most recently August 11, with the most recent information.
Because of widespread wildfires in British Columbia and elsewhere, much of the Pacific Northwest, including Seattle, is covered by a thick layer of smoke for about a week, coming through at at the same time as a heatwave. The thick smoke blanket—and with it, diminished air quality—is even stretching down to Portland.
The smoke cloud is so thick and widespread that it’s clearly visible from space—although it’s started to dissipate. But what does it mean for people here on the ground?
How bad is the smoke?
As of Friday afternoon, most monitoring stations on the Washington State Department of Ecology’s air quality map show Seattle’s air as unhealthy for sensitive groups. It’s a slight uptick in quality from earlier this week, which was largely just plain unhealthy, but not quite back to last weekend, which showed multiple points in Seattle as good.)
The good news: Puget Sound Clean Air Agency (PSCAA) estimates that the air quality should be good by tomorrow.
Throughout the ordeal, air in Seattle had been rated anywhere from healthy to unhealthy by various agencies, including PSCAA, PNW Smoke Cooperators (a collection of county, state, and federal agencies, plus Indian tribes, that work together to map the smoke’s progress) and the Washington State Department of Ecology.
As of Wednesday afternoon, Smoke Cooperators’ map shows more moderate air ratings, which is a healthier rating than Department of Ecology’s map—but they note to use the “more stringent of the two” if there’s any discrepancy.
Unhealthy for sensitive groups is around the middle of the rating scale, which goes higher to “unhealthy,” “very unhealthy” and “hazardous”—but we haven’t had to worry about the latter two in Seattle. (Other parts of Washington have occasionally dipped into very unhealthy.)
What does that mean for me?
Here’s what that unhealthy air quality for sensitive groups means, according to the Department of Ecology: “More people than average may have breathing problems or have worsened symptoms of existing asthma or lung disease,” says their guide to the ratings.
Those with conditions that could be worsened by the smoke, like asthma or a history of strokes, “should limit time spent outdoors,” the guide continues.
The Washington State Department of Health has even more detailed recommendations, including how to tell if the smoke is adversely affecting you.
Is there a burn ban?
Yes. As of Friday morning, the state one burn ban is still back on for Kitsap, Pierce, King, and Snohomish counties. That means no charcoal barbecues, no campfires, no firepits, no fireplaces.
Why is the smoke reaching this far?
“Nature’s air conditioning is broken,” a spokesperson for the National Weather Service told the Seattle Times.
What does that mean? The wind patterns aren’t running like they normally do in this region. Instead of the wind we normally get from the Pacific, we’re getting air blowing from inland and north from British Columbia. This is contributing to the heatwave, and also bringing that smoke in.
How long will the smoke last?
For most of the past week, the answer has been “depends on what the wind does.” Here’s the good news: It’s doing the thing. Marine air is finally blowing back into the region, causing the smoke to lift. (That also means a little relief from the heat wave.)
- You Can Actually See The Smoke Of The BC Wildfires From Space [Buzzfeed]
- BC wildfire smoke pollution now unhealthy for all in Portland [KGW]
- Puget Sound Clean Air [PSCA]
- Washington Smoke Information [PNW Smoke Cooperators]
- Washington Air Monitoring [DoE]
- Washington Air Quality Advisory for Smoke and Other Fine Particle Air Pollution [DoE]
- Smoke From Fires [DoH]
- NWS Seattle [Twitter]
- Cool, marine air is blowing away the B.C. wildfire smoke right now [Seattle Times]