Heatwave and wildfires bring clouds of smoke to Western Washington. How long will this last?

Wildfires are raging in Oregon and a heat inversion will keep skies smoky and the air dirty in Pierce County on Friday. Highs of 32 degrees Celsius are expected in Tacoma.

A heat warning is in effect.

A red sun rose through a tobacco-colored sky on Friday due to a temperature inversion, according to National Weather Service meteorologist Harrison Rademacher.

Normally, hot air near the ground would rise, carrying with it the harmful small particles from vehicle exhaust and other sources. Heat inversion traps this bad air closer to the ground.

Meanwhile, smoke from the Oregon fires remains mostly in the air, Rademacher said, except near Mount Rainier. The smoke density will increase by Saturday, he said.

Dirty air

According to the Puget Sound Clean Air Agency, Pierce County was more affected by dirty air on Friday compared to King County.

“Pierce County and the foothills of the Cascade Mountains may be unhealthy at times for sensitive groups,” it said.

People sensitive to polluted air have been advised to stay indoors. The same conditions are expected on Saturday, the agency said.

Relief in sight

Temperatures will drop on Saturday as northwest winds bring cooler air from Canada. Highs in Tacoma will be between 29 and 30 degrees on Saturday, Rademacher said.

Highs on Sunday will be around 80 degrees as temperatures continue to drop.

Next week the weather will feel more autumnal with highs around 20 degrees and the possibility of showers.