California wildfire smoke makes its way to Western Pa.

Friday evening’s hazy skies were the result of smoke traveling from California, where wildfires are raging.

The smoke traveled through jet streams to the Midwest and East Coast, according to National Weather Service meteorologist Jenna Lake.

It isn’t uncommon for this to occur if the western states experience several wildfires, Lake said.

Despite the smoke, Western Pennsylvania’s air quality was not considered dangerous on Friday, Lake said. Alerts would be sent out if it was dangerous.

Lake anticipates the haze will remain in the region until Sunday at the latest.

There are 13 wildfires blazing across California, the San Francisco Chronicle reports.

The Mosquito Fire, California’s largest wildfire the year, has burned across 100 square miles in the northern part of the state since it ignited on Sept. 6, according to the Sacramento Bee.