(LOS ANGELES) — As hundreds of firefighters battled a raging wildfire on Thursday in the steep mountains north of Los Angeles, cooler weather sweeping into Southern California aided their fight, fire officials said.

The so-called Bridge Fire, which is burning in the Sheep Mountain Wilderness in the Angeles National Forest, saw “minimal” growth on Thursday as winds died down and humidity increased, officials said in their most recent update, posted at about 4 p.m. Thursday.

But the fire’s containment was still at zero percent as of that update, fire officials said. The blaze by then had spread to about 51,580 acres that straddled Los Angeles and San Bernardino counties.

“Firefighters made great progress on the ground, aided by aircraft to attack the fire aggressively 24 hours per day,” the California Department of Forestry and Fire Protection said.

About 480 firefighting personnel were working to contain the fire, which was ignited Sunday and was the largest of several active blazes in Southern California.

The three largest blazes burning on Thursday covered a total of more than 110,000 acres and threatened tens of thousands of structures, according to fire officials.

The Line Fire in San Bernardino County was spread over about 37,207 acres with 21% containment, Cal Fire said. That fire had destroyed or damaged by early Friday at least four structures, with some 65,000 others threatened, officials said.

And the Airport Fire in Orange and Riverside counties covered about 23,453 acres with about 5% containment, Cal Fire said.

Officials with San Bernardino County announced further evacuations for the Bridge Fire late on Thursday, broadening their order near The Baldy Village to including several additional neighborhoods from San Antonio Heights to Wrightwood and east to Cucamonga Peak.

The temperature in Los Angeles was expected to peak on Friday and Saturday at about 78 degrees Fahrenheit, before further cooling next week, according to the National Weather Service.

ABC News’ Marilyn Heck, David Brennan and Bill Hutchinson contributed to this report.

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