SCOTTSDALE, Ariz. (AP) — More than 200 firefighters were battling a wildfire northeast of Phoenix on Saturday that threatened scores of homes and has forced dozens of residents to evacuate.

No structures have been damaged as the wildfire traversed nearly 6 square miles (15 square kilometers) on the cusp of the Boulder Heights subdivision, said Matthew Wilcox, spokesman for a multi-agency wildfire response team.

There were 275 people combatting the fire Saturday as temperatures surpassed 100 degrees Fahrenheit (38 degrees Celsius) before midday, with wind gusts expected in the afternoon.

“We still have unseasonably high humidity, hot weather,” Wilcox said. “We have no wind right now, but gusts were predicted.”

Air tankers and helicopters have helped douse flames from the sky above the Boulder View Fire. The cause of the fire is under investigation. It began about 5 miles (8 kilometers) east of Carefree, just outside northern Scottsdale on the edge of the Tonto National Forest.

The Red Cross set up an evacuation center at a high school in Scottsdale, and shelters for horses and other large animals were established at several locations, including the rodeo grounds at nearby Cave Creek.

In central California, increasing temperatures and low relative humidity this weekend could result in worsening wildfire conditions for the Fresno June Lightning Complex. The complex — made up of three large fires in eastern Fresno County as well as several smaller fires — was nearly 17 square miles (44 square kilometers) and 42% contained by Saturday morning. One structure was confirmed destroyed, and evacuation orders remained in place.

To the north, the Apache Fire in Butte County has destroyed 14 structures and damaged two others since Monday. The blaze was one square mile (2.8 square kilometers ) and 95% contained by Saturday morning.

Crews were making good progress Saturday on the Darlene 3 fire in central Oregon. It was holding at 6 square miles (15 square kilometers) and was 50 percent contained Saturday morning.

The weather has helped firefighting efforts. Low winds, cooler temperatures and high humidity at night all contributed to the firefighters’ progress. It also allowed the Deschutes County Sheriff’s Office to lower the evacuation level for Newberry Estates from Level 3 to Level 2. All other evacuation notices have been lifted for the area west of Highway 97.