According to the National Weather Service in Spokane, this weekend will likely be the last day of temperatures above 90 degrees this year.

“We’re expecting temperatures around 35 degrees for the Spokane area,” said meteorologist Greg Koch. “Especially along the river, temperatures will rise to around 35 degrees.”

This is hot compared to the typical temperatures of over 25 degrees in early September.

“This is well above normal for this time of year,” said Koch.

Spokane is not alone in this. With high temperatures and low humidity expected in the Pacific Northwest, the United States Forest Service warned that weather conditions are ideal for the spread of existing fires and new outbreaks.

An easterly current will cause cooling in the eastern United States, Koch said, which in turn will lead to a buildup of heat over the continent and drive the heat wave over the Rocky Mountains to the West Coast.

“While these seasonal easterly winds are not expected to be as intense as the Labor Day wind event in September 2020, they may produce some gusts,” the Forest Service wrote in an email. “With this easterly flow, fire managers expect an increase in fire danger. This means it may be difficult to contain new wildfires until the weather calms down again.”

The Inland Northwest is unlikely to see the wind gusts that can cause rapid fire spread, but will likely see increased haze from wildfire smoke from Oregon and central Idaho. This haze could arrive as early as Friday.

Temperatures will return to normal early next week, with highs of over 30 degrees on Monday and a drop to over 25 degrees by Wednesday, Koch said.