At least one firefighter was injured battling a blaze near the upmarket Pacific Palisades neighbourhood, US media said, with reports of several other people having suffered burns.
Vicious gusts fanned the flames, whipping red-hot embers hundreds of meters (yards), sparking new spot fires faster than helpless firefighters could quell them.
As dawn broke, a vast pall of smoke was visible over Los Angeles, with the acrid tang of burning in the air.
City mayor Karen Bass warned that the “windstorm is expected to worsen through the morning” in a post on X early Wednesday.
Some firefighters were facing water shortages at hydrants in the Palisades, the Los Angeles Times reported, in a fire that has so far consumed almost 3,000 acres (1,200 hectares).
At the 2,200-acre Eaton fire around Altadena, north of Los Angeles, an AFP journalist saw emergency workers rushing elderly patients in wheelchairs out of their care facility.
A third fire was burning around Santa Clarita.
The blaze at Pacific Palisades has already claimed dozens of homes in one of California’s most desirable spots, where Hollywood celebrities are among those who live in mutli-million dollar houses.
Emmy-award-winning actor James Woods posted a video showing flames engulfing trees and bushes near his home as he got ready to evacuate, and said all the fire alarms were going off.
“I couldn’t believe our lovely little home in the hills held on this long. It feels like losing a loved one,” Woods said.
Events throughout the area were canceled, including a Tuesday evening red-carpet premiere of Jennifer Lopez’s new film “Unstoppable,” while the Screen Actors Guild Award said Wednesday’s in-person nominations ceremony would be replaced with a press release.
President Joe Biden said late Tuesday that he was “being frequently briefed on the wildfires” and had offered federal aid if needed.
