Wildfire smoke made the air quality unhealthy for everyone in downtown and North Seattle, the Puget Sound Clean Air Agency said Wednesday morning.

The agency said a plume of smoke from the Bolt Creek fire near Skykomish was being blown west to Everett, then south into parts of Seattle, The Seattle Times reported.

Air quality was also listed as unhealthy for sensitive groups in parts of Pierce and Snohomish counties, but reported to be good to the west throughout Kitsap County. By Wednesday afternoon, the agency said the smoke was moving east to Sammamish and the Cascade foothills. That brought a measure of relief, as air quality in western King and Snohomish counties returned to moderate.

AIR QUALITY IN MONTANA DETERIORATES DUE TO WILDFIRE SMOKE

Seattle air quality bad

The air quality in Seattle has plummeted to unhealthy levels due to the Bolt Creek fire blanketing the area with smoke.

The National Weather Service in Seattle said the smoke is expected to stay in the Puget Sound region at least through Thursday, when winds from off the coast are expected to start clearing it out.

Drier, warmer weather this week was causing the fire to creep and smolder more in vegetation, creating more smoke, fire officials said. The fire has burned 15.9 square miles since it started on Sept. 10.

MONTANA WILDFIRE SPREADS OVER 1K ACRES; PERSONNEL CAN'T SAFELY FIGHT ON GROUND

Crews are working toward reopening Highway 2 near the wildfire by next Monday, transportation officials said on Twitter. Arborists with Washington State Parks removed 50 to 60 burned trees near the road Wednesday morning, officials said.

"They continue to remove burned roadside trees that still pose a threat to public safety," officials said.