California Department of Forestry and Fire Protection spokeswoman Roxanne Provaznik says the blaze is 30 percent contained Friday. It has burned 1,650 acres.
She says afternoon thunderstorms significantly dampened the flames.
The fire is burning in highlands northeast of the community of Warner Springs, about 50 miles northeast of downtown San Diego.
Residents of the Chihuahua Valley Road area were advised to evacuate but so far no buildings have burned. A firefighter was injured while on the fire line.
Provaznik says the firefighting effort has so far cost about $1.3 million.