Wildfires burning on the edges of Spokane Washington for a third day have ruined at least 700 buildings and forced tens of thousands of residents to leave their homes in and around the state's second largest city officials said on Monday.

The group of three fires is now the top firefighting priority across the US including the dry Pacific Northwest where many major wildfires have been active for weeks harming air quality over a broad area.

The fires near Spokane have burned more than 8,000 acres since they began on Saturday around the northern suburbs of the city which has about 230,000 residents west of the Rocky Mountain foothills near the Idaho border.

As of Monday some 64,000 people were under immediate evacuation orders up from 4,000 a day earlier according to Benjamin Cossel a spokesperson for the incident command center.

At least 700 structures have burned most of them in residential zones and aerial infrared surveys indicated that possibly another 400 buildings including homes had been damaged or destroyed Cossel said.

No injuries or fatalities reported high chance of change

The cause of the fires remains under investigation.

No injuries or fatalities have been reported so far he said adding there is a high probability that will change in the coming days as flames ease and search teams reach devastated communities still cut off due to intense fire activity.

An unspecified number of people have been reported missing as flames moved from wooded areas into neighborhoods and commercial zones turning from a wildfire to an urban fire he said.

Roughly 1,100 firefighters were fighting the Spokane fires as of Monday Cossel said a small part of the more than 29,200 personnel assigned to wildfires nationwide most heavily in Oregon Washington state and Idaho according to the National Interagency Fire Center in Boise.

The agency reported more than 100 large new wildfires on Sunday across 15 states the bulk of them in the Northwest stretching resources thin across the region.

Explosive fire behavior

North of the US Canadian border flames continued to burn across British Columbia where record drought conditions have led to what officials over the weekend called explosive fire behavior in the southern part of that province.

Aerial firefighting assets in Spokane were so far limited to four fixed wing tanker aircraft with no water dropping helicopters currently available Cossel said.

Fire managers hoped their crews could make greater progress during a narrow window of cooler less windy weather expected on Monday and Tuesday before extremely high temperatures low humidity and gusty conditions return at midweek Cossel said.

Even though fire activity in some spots has eased compared with Sunday authorities were reluctant to lift evacuations in most of the fire zone.

The worst thing in the world is to let people go home only to have to evacuate them again 24 to 48 hours later Cossel said.

As of Monday firefighters had yet to contain any of the three Spokane area fires officials said.

The Interagency Fire Center has documented a total of 44,722 wildfires year to date nationwide the highest number for this time of the year in at least a decade with nearly 5.2 million acres consumed the most from January to early August since 2022.

The conditions driving the increase in wildfire activity in North America Europe and elsewhere in recent years especially periods of prolonged drought and extreme heat are largely a function of human caused climate change according to scientists.