SEATTLE -- Cleaner air from the Pacific has started pushing onshore, clearing out some smoke and improving air quality in Western Washington.
"Air quality continues to improve as onshore flow pushes marine air into the area," the National Weather Service wrote in a tweet. "Latest smoke forecast shows continued improvement today at the surface, was some lingering smoke aloft."
Q13 News Meteorologist Katie Boer said areas like Olympia, North Bend and Lake Forest Park were still seeing and smelling smoke Thursday.
But other areas like Everett, Seattle and Arlington weren't even registering smoke Thursday morning.
Unhealthy air filled with smoke from wildfires blanketed the Northwest earlier this week.
Washington state had the worst air quality in the country, according to the National Weather Service.
The smoke reached levels that were unhealthy for everyone in Seattle and nearby areas, the Puget Sound Clean Air Agency said.
In the central Washington cities of Chelan and Wenatchee the air quality Wednesday reached the hazardous level, prompting Chelan County officials to distribute masks.
According to the National Interagency Fire Center, 13 large wildfires have burned more than 211 square miles in Washington state this year, while in Oregon, 10 large fires have scorched over 256 square miles the Seattle Times reported. About 600 wildfires are burning across British Columbia.
The Oregon Department of Environmental Quality said Wednesday that the air quality in Portland and Medford was unhealthy.
An air quality alert for eastern Washington and northern Idaho has been extended into Friday morning.
Staying healthy when it's smoky
If you see a haze, smell smoke or know of a wildfire in your area or a place you plan to visit, check the Air Quality Index to see whether you need to limit your time outdoors.
When advised to stay inside, keep your windows and doors closed. It's OK to keep the air conditioner running, but make sure the filter is clean, and close the fresh-air intake to prevent smoke from entering, according to the CDC.
It's also important to keep indoor air clean by not burning candles, using the fireplace or gas stoves, or smoking. Running a vacuum can also keep particles circulating in the air.
Dust masks actually trap large particles and don't protect your lungs from smoke inhalation, but a mask that uses a filtering respirator can offer some protection. The CDC also has tips for how effective different types of masks can be, depending on your exposure.
Even if the air outside or in your home looks clear, it may not be free of harmful microscopic particles, especially if the wildfires and smoke persist for weeks.
Pediatric pulmonologists at Children's Hospital Colorado's Breathing Institute also recommend changing your clothes if you've been outside, rinsing out red, irritated eyes and drinking fluids to keep from being dehydrated. Parents should seek emergency care for their children if they experience real difficulty breathing or a change in their level of consciousness.
There is a low risk of long-term effects of wildfire smoke exposure for healthy individuals.