Dry Santa Ana winds, blowing westward from the California desert, could reach 75 mph and spread the blaze to America’s second largest city.
The Skirball Fire in Los Angeles has forced hundreds of residents in the wooded hills near the affluent Bel-Air neighborhood to evacuate and charred more than 150 acres.
Homes belonging to celebrities, including Paris Hilton and Chrissy Teigen, and Rupert Murdoch’s Moraga Estate winery have been evacuated as the fire spread.
In the San Fernando Valley north of Los Angeles, the Creek Fire destroyed at least 30 homes, blackened more than 12,000 acres and forced the evacuation of 2,500 homes.
Another blaze, the Rye Fire, threatened more than 5,000 homes and structures northwest of Los Angeles.
“These are days that break your heart,” Los Angeles Mayor Eric Garcetti said Wednesday during a news conference. “These are also days that show the resilience of our city.”
The fires are most likely to spend to the areas surrounding the Rye Fire, Skirball Fire and the Creek Fire in Los Angeles.
But there are also fears that flames could spread from the terrifying Thomas Fire, the largest of the ferocious blazes, which is further away.
Thomas Fire has destroyed more than 150 homes and engulfed more than 90,000 acres in Ventura County, which is northwest of Los Angeles.
The blaze is now closing in a Ojai – a city loved by spiritual seekers, health enthusiasts and celebrities – in the county.
Skirball threatened media magnate Rupert Murdoch’s Moraga Estate winery. Murdoch said: “We believe the winery and house are still intact.”
Teigen tweeted: “Never thought I’d get to actually play what I thought was a hypothetical game of what would you grab if there were a fire.
“So far all I have is Luna, some limited edition Oreos and my Spike TV award.”
Thomas Fire threatened homes in Santa Paula and flames were seen “marching west” on Wednesday night, CBSLA’s Crystal Cruz said.
“We’ve been hearing sparks and loud booms and we think it’s power lines or transformers that have caught fire and blasted off,” said Ms Cruz.
“The fire was on top of the hillside and now it’s much closer, huge flames ripping down the mountain, sending smoke and flames west. It almost looks like a volcano erupted with lava flowing down the hill.”