Wildfires roared Sunday across much of California, forcing thousands to evacuate homes as the most populous US state sweltered in record heat and flames menaced thousands of structures.

Some 8,000 people were sent fleeing as thousands of firefighters were battling 14 large wildfires throughout the state, according to the California Department of Forestry and Fire Protection, known as Cal Fire.

The Alamo fire had scorched 23,867 acres (96.58 square kilometers) after starting in San Luis Obispo County and spreading to Santa Barbara County along the state's central coast, officials said.

That blaze, currently the state's largest active fire located approximately midway between San Francisco and Los Angeles, was 15 percent contained, according to Cal Fire.

In Santa Barbara County some 1,000 firefighters were racing to contain the Alamo fire -- which prompted some 200 people in a remote area to flee -- with help from water-dropping helicopters.

Fire containment efforts were particularly aimed Sunday at guarding mountain peaks holding vital infrastructure, according to the Los Angeles Times newspaper, such as a high-voltage line that powers neighboring cities.

- Flames and ash -

More than 3,500 people had fled the Whittier fire in Santa Barbara County that started on Saturday afternoon as temperatures hit a sizzling 110 degrees Fahrenheit (43 degrees Celsius), officials said.

It quickly grew to engulf some 7,800 acres and was just five percent controlled, authorities told journalists at the Los Padres National Forest headquarters.

That wildfire had destroyed 20 structures and threatened 150 more, according to Cal Fire. It ravaged much of an outdoor residential education center that is also home to a local Boy Scouts chapter.

All staff members who were on site of the Outdoor School at Rancho Alegre were safely evacuated, the group said in a statement.

"We have, however, lost our dear animal friends in the nature center and many of the state on site have lost most of their belongings," the organization posted on its Facebook page.

Area resident Sarah Gustafson told the LA Times that she was getting her tires changed when she saw a pillar of smoke rising and realized her six cats were trapped at home.

She rushed back and managed to save the animals, and described a sky painted orange and black and "flames up on the ridge."

"It was terrifying," she told the paper. "When I got home it was smokey with ash."

She then scrambled back to a Red Cross shelter parking lot where she and her cats spent the night.

Most of southern California including metropolitan Los Angeles has been in the grips of a blistering heat wave, with temperatures exceeding 100 degrees.

California Governor Jerry Brown in April declared the official end of the state's drought that lasted more than five years.

But he kept in place water reporting requirements, as well as bans on practices such as watering during or following rainfall and hosing off sidewalks.

Source: AFP