Air quality west of the Cascades deteriorated rapidly over the course of Saturday as smoke from nearby fires settled over the Puget Sound region. By some measurements, Seattle had the most toxic air of any major city in the world by late afternoon.
Air quality readings up and down the Interstate 5 corridor displayed unhealthy levels for everyone, according to the Washington State Department of Ecology — not just sensitive groups, as they’d shown earlier in the day.
Driving the rapid degradation is the fast-growing Bolt Creek fire between Skykomish and Index, north of Highway 2. Ash from the fire, which closed Stevens Pass and spurred evacuation orders for hundreds, rained down across the region and even across the water on the Olympic Peninsula.
The smoke will likely hang around through at least Sunday before winds from the ocean push the unwelcome guest east toward Spokane and Northern Idaho on Monday morning.
The hazy skies, which have dampened sunrises and will likely turn Saturday’s full moon an eerie orange, are the first to settle over Western Washington this year, ending what had been a mercifully clear and clean summer.
A long, cool spring initially kept wildfires at bay in the state and favorable winds created a protective bubble west of the Cascades.
But fire activity picked up amid high temperatures, strong winds and low humidity — gusts near the Columbia River Gorge topped 50 mph. The winds have shifted west in recent days, bringing smoke from the Chilliwack and Pasayten fires in the North Cascades first to Whatcom and Skagit counties, then south into Snohomish and King counties.
The new fire near Skykomish erupted Saturday morning, blackening skies as it grew to over 2,000 acres.
The Puget Sound Clean Air Agency warned that smoke from the Skykomish area’s Bolt Creek fire could cause the air to become unhealthy for all groups. That came to pass late afternoon. Under these conditions, everyone is advised to stay inside when possible and avoid strenuous activity, especially sensitive groups.
Wildfire smoke continues in our region. Expect AQ that is MODERATE to USG through the weekend. A new fire creating a lot of upper-level smoke is getting pushed NW towards Marysville. If that smoke comes down, it could lead to UNHEALTHY AQ in those areas. https://t.co/VhUWCQElpC pic.twitter.com/MPVwlwl5sJ
The temperature was forecast to touch 90 degrees through the weekend. However, one silver lining of the smoke is that it may cool things down a bit, deflecting some of the heat and keeping the temperatures in the low 80s Saturday, said Maddie Kristell, meteorologist with the National Weather Service in Seattle.
The National Weather Service has issued a red flag warning for the region, meaning fire risk is high. In response, King County Fire Marshal Chris Ricketts issued a Stage 2 burn ban for the county, prohibiting all outdoor recreational fires. Approved cooking and heating appliances that use gas and charcoal are still allowed.
Mount Rainier National Park issued a ban on all fires within the park.
Ocean winds will begin their eastward march Sunday, lowering temperatures and hopefully clearing the air of smoke on the Washington coast. That relief likely won’t reach the Puget Sound region until Monday, said Kristell. When it does, the weather will start to look more like a normal September, with temperatures in the high 60s and scattered clouds.
CORRECTION: Chris Ricketts’ last name was misspelled in an early version of this story.
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