Firefighters making big strides against a cluster of blazes near Spokane, Washington, scrambled on Wednesday to secure their gains as they anticipated ​a return of extremely hot, dry weather in the days ahead. Officials said crews had carved buffer lines around a trio of fires threatening the state’s second-most populous city. The blazes have destroyed hundreds of buildings and forced tens of thousands of people from their homes since Saturday.

However, full containment, in which a wide corridor of ground has been scraped clean of combustible vegetation around a fire’s perimeter, has yet to be achieved, authorities said.

“With primary containment lines now in place, crews are focused on strengthening those lines through aggressive mop-up and extinguishing pockets of heat near homes and other structures to reduce the risk ‌of additional damage,” ‌the Spokane-area fire command said.

The Spokane fires were ranked as the ​No. ‌1 ⁠firefighting priority in ​the ⁠US as a whole, including the drought-parched Pacific Northwest, where dozens of major wildfires have burned for weeks, fouling air quality across a wide region with smoke and soot.

A total of 94 major wildfires were burning in 13 US states, most of them in the West, and more than half of those in Oregon and Washington, according to the National Interagency Fire Center in Boise.