Authorities ordered residents in parts of Carpinteria and Montecito to evacuate early on Sunday as the Thomas Fire edged closer to the city of Santa Barbara, about 160km northwest of Los Angeles.
The blaze, the worst of six major fires in Southern California in the last week, has already blackened 173,000 acres (62,726 hectares), consumed hundreds of structures and left nearly 90,000 homes and businesses in the area without power.
The combination of Santa Ana winds and rugged terrain in the mountains that run through Santa Barbara and Ventura counties have hampered firefighting efforts, and officials said the Thomas Fire was only 15 percent contained on Sunday.
The National Weather Service said winds of up to 55 miles (88 km) per hour were expected on Sunday, up from top speeds of 40 miles per hour on Saturday.
The fires raging across Southern California have forced the evacuation of some 200,000 people and destroyed nearly 800 structures.
Governor Jerry Brown, who surveyed the devastation in Ventura on Saturday, said the ferocious fires in December may be "the new normal" for the state, with climate change exacerbating the drought conditions that stoke such blazes.
At the Ventura County Fairgrounds, evacuees slept in makeshift beds while rescued horses were sheltered in stables. A steady stream of rescue workers streamed in and out of the entrance early on Sunday.
Peggy Scissons, 78, arrived at the shelter with her dog last Wednesday, after residents of her mobile home park were forced to leave. She has not yet found out whether her home is standing.
"I don't know what's gonna happen next or whether I'll be able to go home," she said. "It would be one thing if I were 40 or 50, but I'm 78. What the heck do I do?"
James Brown, 57, who retired from Washington State's forestry service and has lived in Ventura for a year, was forced to leave his house along with his wife last week because both have breathing problems.
"It brought back old memories, fighting forest fires," said Brown, who is in a wheelchair. "We knew a fire was coming, but we didn't know it would be this bad."
Thus far, the fires have been blamed for a single death, after a 70-year-old woman who died Wednesday in a car accident as she attempted to flee the flames in Ventura County. Scores of horses have died, including at least 46 at a thoroughbred training facility.
Some of the other fires, in San Diego and Los Angeles counties, have been largely controlled by the thousands of firefighters on the ground this week.
Both the Creek and Rye fires in Los Angeles County were 90 percent contained by Sunday morning, officials said, while the Skirball Fire in Los Angeles' Bel Air neighbourhood was 75 percent contained.
North of San Diego, the 4,100-acre (1,659 hectare) Lilac Fire was 60 percent contained by Sunday.
Brown issued emergency proclamations last week for Santa Barbara, San Diego, Los Angeles and Ventura counties, freeing up additional resources to fight the infernos.
