"Fire raged through that park so quickly there was no way of stopping it. It was like matches," Schwarzenegger told a news conference on Sunday.
"This has been a very tough few days for the people of Southern California. We had the perfect storm - high winds, high temperatures and it is very, very dry."
In one of the worst-hit areas - a Los Angeles mobile home park in the foothills of Sylmar where fire devastated 500 trailers overnight on Friday - police using dogs began a search for bodies of the elderly or disabled residents who the authorities fear may not have been able to get out in time.
Officials said wildfires have scorched more than 20,000 acres in foothills north of Los Angeles, in hillsides in Orange County to the south, and in the celebrity enclave of Montecito near Santa Barbara.
At least 210 homes in Montecito were gutted on Thursday before the blazes were bought under control.
In Orange County, more than 40,000 residents fled at short notice as fire jumped across highways and flames towered hundreds of feet in the air.
Janet Cunningham, 91, said she was given five minutes by a police officer to get out of her Yorba Linda home at dawn on Sunday.
"I was so nervous. Five minutes is so little time… I tried to get my clean panties out of the drawer," she said.
"I just had eye surgery on Thursday and I'm not supposed to drive. [The police officer] said I'd have to drive myself out. I don't know how I didn't have a heart attack."
But while most of the blazes are likely to take several days to extinguish, there was some relief on Sunday as wind gusts of up to 50kph that had sent embers flying for miles over the previous three days died down.
Sam Padilla, a Los Angeles County fire inspector, said that the fire was not so wind-driven on Sunday.