ENTIAT, Wash. (AP) — A wildfire burning grass, brush and scattered timber in central Washington has grown by about 2 square miles, but officials reported good progress in protecting homes in the area.

Fire operations spokesman Rick Acosta said 763 personnel continued fighting the Mills Canyon fire, which by Saturday morning had grown to about 34 square miles near Entiat, roughly midway between Seattle and Spokane.

Despite hot weather, the fire did not spread appreciably during the day Saturday, he said. It was about one-fifth contained, and smoke was affecting the air quality in Entiat and other nearby towns.

“We are seeing moderate fire behavior today, but it’s not making runs and getting ahead of itself like it was,” Acosta said. “We’re hoping to keep it where it is.”

There was more moisture in the trees above 3,000 feet in elevation, and on hills where the fire incinerated dead and downed logs to thin lines of ash, some of the standing pines remained green, he said.

Residents of several dozen homes had been told to evacuate. Officials said crews did good work protecting more than 100 houses along Highway 97A, and on Saturday they were working to protect 14 homes along Roaring Creek, near the fire’s northern edge. Another priority was digging fire lines along the western edge to contain the blaze.

Crews were also using aircraft to dump fire retardant or buckets of water.

Authorities worried about the hot weather over the next few days and warned that thunderstorms Sunday and Monday could start more fires. State officials have extended an outdoor burn ban to include all 13 million acres of lands that the state protects.