Strong winds that have powered the third-largest wildfire in California’s history are expected to further fuel a blaze that has burned 267,500 acres.

Nearly 8500 firefighters are battling the so-called Thomas Fire in Southern California, which began on December 4 and has destroyed more than 1000 structures and threatened 18,000 more, including homes in the wealthy town of Montecito just outside the coastal city of Santa Barbara.

While the winds were expected to ease on Sunday near Santa Barbara, north-east wind gusts up to 90km/h were forecast through Sunday for parts of Ventura and Los Angeles counties, National Weather Service forecasters said.

The blaze, centered less than 160km north-west of downtown Los Angeles, has forced evacuations that turned neighbourhoods into ghost towns and filled the air with smoke.

The fire is now 40 per cent contained despite hot Santa Ana winds that have powered its expansion, at times sending embers far ahead of its main flank.

The hot Santa Ana winds have propelled the fire’s expansion in California. Photo: AP

Firefighters were employing more than 970 fire engines and 34 helicopters to battle the blaze.

“It is a beast,” Santa Barbara County Fire Department Division Chief Martin Johnson told a news conference on Saturday. “But we will kill it.”

Five of the 20 most destructive fires in recorded history ravaged the state in 2017, according to Cal Fire.

The Thomas fire, the seventh-most destructive in state history, forced many schools to close for days, shut roads and drove hundreds of thousands from their homes. It was also responsible for poor air quality throughout Southern California.

On Saturday, evacuation orders were issued for parts of Santa Barbara County as high winds whipped the fire through bone-dry terrain.

The threatened town of Montecito boasts the mansions of Oprah Winfrey, Ellen DeGeneres and many other celebrities.

Five of the 20 most destructive fires in recorded history ravaged California in 2017. Photo: AP

Winfrey referred to the fire threat on Twitter.

“Still praying for our little town. Winds picked up this morning creating a perfect storm of bad for firefighters,” she tweeted though it was not clear if the former talk show host was at her home.

In Montecito on Saturday, smoke billowing from nearby canyons and pushed by the high winds choked the air, hindering aircraft from dropping flame retardant, the Governor’s Office of Emergency Services said. An evacuation order for the city of Ventura was lifted on Saturday morning.

Cal Fire engineer Cory Iverson, 32, died on Thursday while battling the flames near the Ventura County community of Fillmore. The blaze’s first fatality, he died of smoke inhalation and burns, the Ventura County Medical Examiner’s office said.