The fast-moving wildfire about 90 miles east of Los Angeles broke out just after noon and was moving westward through largely undeveloped foothills of the San Bernardino Mountains, but it was dangerously close to subdivisions to the south, in Banning.
At least 425 firefighters were working to gain control of the fast-moving fire, which has destroyed one structure, said Jody Hagemann, spokeswoman for the county fire department. Six helicopters and six air tankers were making water drops.
Authorities ordered the evacuation of homes on two streets, but the number of people affected was not immediately known.
Joe Kiener, 53, was on his lunch hour at the childhood home where he still lives when he saw smoke approaching. He and his dog were already pulling out when a deputy came up and told him to evacuate. A few hours later the house was destroyed.
"It's a total loss," Kiener told the Riverside Press-Enterprise. "It really hasn't hit me yet. But it hurts me to lose the house."
The house next door was untouched after a timely wind change.
"It was close!" Kiener's neighbor David Pena said. "God's grace, man. It's a miracle."
Winds of 29 mph were driving the fire, and if they continued, the fire could reach communities in Cherry Valley and Beaumont.
Much of Southern California was under red flag warnings for fire danger due to heat, wind and low humidity levels.
In Northern California, firefighters were battling fires fueled by gusty winds in wine country.
In Sonoma County, the Yellow Fire north of Calistoga was less than half contained after burning 125 acres. The Silverado Fire near Yountville, in Napa County, burned an even smaller area and was 75 percent contained.
State fire spokesman Daniel Berlant said neither fire was threatening structures, but the blazes across of California could be an ominous sign.