Photo: Twitter - NWS Los Angeles

Southern California residents were bracing for another day of gusty Santa Ana winds, along with a chance of record high temperatures from a fall heat wave.

Temperatures could reach 100 in the hottest coastal and valley locations, according to the National Weather Service.

Red flag conditions of extreme fire danger from heat and gusty winds coupled with low humidity and tinder-dry brush were projected to continue through Thursday night from coastal counties northwest of Los Angeles down to the Mexico border.

Some mountain areas could see wind gusts of up to 45 mph.

The Los Angeles County Fire Department planned to place more than a dozen extra fire engines and their crews in brushy, hilly areas west and north of Los Angeles to rapidly respond if wildfires erupt.

"Even though we did have some recent rain, it's still very dry out there...and with the Santa Ana winds, if something catches, the potential for it to spread is that much greater," Inspector Joey Marron said.

Already this year, California wildfires have destroyed dozens of homes as they burned through drought-parched mountains and ranchlands.

"We had all those fires at the beginning of the summer, which is not our typical fire season," Marron said. "For us here in Southern California, with the drought and the dryness, it's all year round for us."

An expanding high-pressure ridge was expected to push temperatures 15 to 20 per cent above normal in some areas before the heat wave begins to ease slightly on Friday, according to forecasters.

On Wednesday, hot winds gusting out of the mountains drove up temperatures and fanned several small brush fires in the San Fernando Valley of Los Angeles. Water-dropping aircraft and ground crews contained them without damage to any homes.