Stan Lake, the state deputy fire chief, said: "We still have a long way to go with this fire season ... we're not out of the water yet."
The fires claimed the lives of a homeless man taking shelter under a flyover and a motorist who crashed on a smoke-enveloped road the day before.
The two fires are the first major conflagrations of southern California's fire season and were the largest of several that have swept the state since the weekend, devastating 11,000 hectares of land so far.
About 2,000 people were forced to flee after one fire razed 1,200 hectares of land on the Camp Pendleton US marine base, 130km south of Los Angeles.
Last year's, 30 wildfires swept through southern California in a single week, killing a dozen people, destroying 2,000 homes and forcing 500,000 residents to flee.