Large parts of Spokane County, Wash., including residences and at least one hospital, were under mandatory evacuation orders on Saturday as strong winds were propelling wildfires into residential areas.

At the same time, more than a dozen other fires were also burning across the state, mostly in less populated areas, affecting about 250,000 acres.

“This is an extraordinary fire season,” Dave Upthegrove, the state’s commissioner of public lands, said at a Saturday evening news briefing. “This is not normal.”

Nearly 3,000 acres in eastern Washington were burning late Saturday afternoon, pushed by wind gusts up to 45 miles per hour, according to the disaster tracking platform Watch Duty. The largest, the Old Trails fire, sparked around noon and had grown to about 3,500 acres by 10 p.m. local time.

Large parts of Spokane County were under the highest level of evacuation order, Level 3, and officials urged residents in the evacuation zone to leave immediately. Videos circulating on social media showed billowing smoke and orange-colored skies as cars in slow-moving traffic tried to get away from the fires. Officials said no injuries or deaths had been reported as of Saturday evening.

About 4,000 firefighters were working across the state to put out the fires, and the National Guard had also been deployed. Personnel or equipment from more than a dozen other states were also assisting, Mr. Upthegrove said.

Washington has been experiencing a record-breaking wildfire season, in part due to drought and heat. More than 1,000 fires have burned this year, covering about 425,000 acres, according to the Washington Department of Natural Resources.

On Saturday, forecasters with the National Weather Service had issued their most urgent alert — “a particularly dangerous situation” red-flag warning — for large parts of eastern Washington and northeastern Oregon. It marked the first time such a warning was issued in Washington, officials said.

Gov. Bob Ferguson also declared a statewide state of emergency, pointing to drought conditions, unusually high temperatures and strong winds.

In Spokane, about 4,000 structures were at risk of burning, according to George Geissler, the top forester in Washington State. A veterans’ hospital was evacuated, and all patients requiring ongoing medical care were sent to nearby hospitals, the hospital said on social media.

Mayor Lisa Brown of Spokane said that some city facilities, including a water treatment plant and a wastewater facility, had also been evacuated. An evacuation shelter opened at the Spokane Convention Center.

Spokane County commissioners issued a disaster declaration during an emergency meeting on Saturday evening.

On Saturday evening, about 28,000 customers of the company Avista were without power in the Spokane area, the utility’s chief executive, Heather Rosentrater, told commissioners. She said about 6,700 of those outages were the result of planned shutoffs to reduce safety risks.

Officials said it was too early to determine the full extent of the damage in Spokane.

“When the sun rises in the morning, I think we’re going to be in shock to see some of the scenes that emerge,” Maj. Gen. Gent Welsh, the Washington National Guard commander, said at the briefing. He called the situation “the roughest combination of series of events I’ve seen in my career.”

Spokane County’s sheriff, John Nowels, said that dangerous fire conditions were likely to continue for 24 hours, adding that it was unclear when evacuees could return home.

Ms. Brown warned that shifting winds could change the fire’s path and bring heavier smoke to the area. She urged residents to stay up to date on evacuation orders.