Temperatures will plummet across the northwestern United States as chilly storms roll across the region into the first week of October.

The chill may come as a shock for some residents given the recent stretch of unseasonably warm conditions.

Long sleeves, hats and jackets will need to be kept close at hand as the cool air takes hold into next week.

“As cold air in the upper atmosphere moves into the region, temperatures will go from well above normal and, in some cases record-breaking, to below normal this weekend,” AccuWeather Meteorologist Ryan Adamson said.

Highs in the 40s, 50s and 60s will settle in over the weekend and into the first days of October following several days in the 70s and 80s this week.

Seattle’s high temperature around 60 degrees Fahrenheit early next week will be a far cry from the daily record high of 86 that was felt on Thursday.

Temperatures most mornings into next week will be in the 40s along the coast, 30s across the Inland Empire and 20s over the northern Rockies.

Waves of chilly air will rotate counterclockwise from Canada around the main storm over the Northwest. Bouts of rain and snow showers will push inland with each wave.

“Anyone planning on heading to Yellowstone National Park will need to be prepared for winterlike conditions later Saturday and into Sunday,” Adamson said.

“While the rain and snow will assist in firefighting efforts, winds accompanying the storm could cause any existing fires to spread,” he added.

Fire crews could face erratic wildfire behavior and breached containment lines.

The number of wildfires has significantly lessened following a cool and unsettled middle of September in the Northwest. As of Friday morning, Sept. 29, there are a little over one dozen active large blazes in Montana, Oregon and Washington, according to the National Interagency Fire Center.

An even more potent wave of cold air will rotate in early next week, potentially leading to a more significant rain and snow event for the northern Rockies and Plains on Monday and Tuesday. This chilly wave will also reach far to the south, knocking temperatures 5-10 degrees below normal in Redding, Fresno, Sacramento and Los Angeles, California, as well as Las Vegas.