VENTURA (California) • Firefighters yesterday worked to gain further control of a wildfire, the fifth-largest in California's history, as relentless wind gusts and bone-dry weather conditions were expected to persist.
The blaze, known as the Thomas Fire, grew but at a slower pace, said the California Department of Forestry and Fire Protection.
It has burned more than 93,000ha in Ventura and Santa Barbara counties, about 160km north-west of downtown Los Angeles, and was only 20 per cent contained as of Monday night.
Strong wind gusts of up to 65kmh and extremely low humidity expected until tomorrow will continue to pose a challenge to firefighting efforts, the National Weather Service was quoted as saying by Reuters.
"That combination of winds and very low relative humidity leads to critical fire conditions and can allow for a potential of significant fire growth and fire behaviour," National Weather Service incident meteorologist Rich Thompson said at a community meeting on the fire on Monday evening.
Some of the other fires burning over the past week in San Diego and Los Angeles counties have been largely controlled by the thousands of firefighters on the ground and many of the evacuation orders in those areas had been lifted.
The Creek Fire and Rye Fire in Los Angeles county were both at least 90 per cent contained, officials said, while the Skirball Fire in the posh Bel Air neighbourhood of Los Angeles was 85 per cent contained.
North of San Diego, the 1,660ha Lilac Fire was 90 per cent contained on Monday, after destroying 151 structures. Liberty Fire in Riverside county was contained on Sunday.
Together, the six blazes in California have scorched an area bigger than New York City and Boston combined, reported CNN. In total, the fires have destroyed more than 1,000 structures since last week.
Despite the intensity of the fires, the authorities have reported only one fatality - a 70-year-old woman who died in a car crash while fleeing a blaze.
About 7,000 firefighters were battling the Thomas Fire, which has destroyed about 800 structures, including more than 680 homes.
Dry vegetation that has not burned in 50 years is acting as fuel for the fire in the mountains south-east of Santa Barbara and north-west of Ventura, said Mr Ian McDonald, a public information officer for the Thomas Fire.
"Because the slopes are so steep and the terrain is so rocky, it is actually quite dangerous," he said. "We are not going to put firefighters in harm's way halfway up a steep rocky slope. We are going to wait for the fire to come to us and extinguish it where it is safe."
The limited visibility also made it difficult to tackle the blaze.
Public schools in Santa Barbara and some school systems nearby have cancelled classes this week and will not reconvene until the annual winter break is completed next month, said Santa Barbara Mayor Helene Schneider.
Celebrities Oprah Winfrey and Ellen DeGeneres, who are reported to have homes in Montecito just outside Santa Barbara, took to Twitter to express concern.
"Our house is under threat of being burned," DeGeneres wrote on Twitter on Sunday. "We just had to evacuate our pets."
California Governor Jerry Brown has warned that climate change meant the state was becoming increasingly vulnerable and wildfires were becoming the "new normal", reported Agence France-Presse.
"The fire season used to be a few months in the summer," he said. "Now it's almost year-long."
Mr Brown has been one of the most vocal critics of President Donald Trump's decision to pull the United States out of the Paris accord on global warming, and he renewed his attacks on the administration over its attitude towards climate change. "Nature is not a political game. Nature is the ground on which we stand, it's the air which we breathe," he said.
This has been California's deadliest year ever for wildfires. More than 40 people died in October when fires swept through the state's wine-producing counties north of San Francisco.
Mr Trump has issued a state of emergency for California, authorising the release of federal funds.