Firefighters battling flames amid a heat wave in Southern California are struggling to gain control of a wildfire that exploded over the weekend to more than 13,000 acres, prompting evacuations and threatening homes, including Michael Jackson’s Neverland Ranch, officials said.

The Lake Fire burning in Santa Barbara County near the Los Padres National Forest was 0% contained as of Sunday morning, according to the California Department of Forestry and Fire Prevention (CAL FIRE).

The Lake Fire is one of 21 wildfires burning in California on Sunday, CAL FIRE said.

Lake Fire in Santa Barbara County

The wildland blaze about 40 miles north of the city of Santa Barbara started on Friday afternoon near Zaca Lake in the Los Padres National Forest.

The Santa Barbara County Sheriff’s Department issued evacuation orders on Saturday night as the blaze grew to 13,264 acres. The evacuation orders included the 5000 block of Figueroa Mountain Road, where Michael Jackson’s former ranch is located, officials said.

Warnings were also issued for residents in the surrounding area to be prepared to evacuate, according to the sheriff’s office.

The wildfire erupted during a heat wave that has enveloped the area and most of California.

“An EXCESSIVE HEAT WARNING through next week continues to affect the fire with high temperatures, drying vegetation and little relief at night. The National Weather Service has reported that a heat wave this intense, this long, has not been experienced in this region in 20 years,” CAL FIRE said in a statement.

The fire grew rapidly on Saturday amid temperatures in the high 90s and with a relative humidity of around 11%.

“When relative humidity decreases, fire behavior increases because fine fuels like grass and pine needles become drier quickly,” according to the Western Fire Chiefs Association (WFCA).

The cause of the fire is under investigation.

Thompson Fire in Oroville

Fire crews were gaining the upper hand on the Thompson Fire, which started on Tuesday in the Butte County town of Oroville and caused the evacuations of nearly 30,000 residents as it grew to 3,789 acres, according to CAL FIRE. The blaze — which destroyed at least 25 structures, including homes — was 86% contained on Sunday.

Firefighters battled both flames and dangerous temperatures on Saturday in the Oroville area ranging from 110 to 116 degrees, according to CAL FIRE.

“For Sunday, hot and dry conditions will continue although high temperatures will be a couple of degrees cooler. However, the heat will still be at very dangerous levels and the EXCESSIVE HEAT WARNING will remain in effect,” CAL FIRE said in a statement.

Most of the evacuations caused by the Thompson Fire were lifted on Saturday.

Basin Fire in San Joaquin Valley

The largest and most stubborn fire in the state, the Basin Fire burning in the foothills east of Fresno in the San Joaquin Valley, was 60% contained on Sunday after burning 14,027 acres, according to CAL FIRE. The blaze started on June 26 in the Sierra National Forest north of Pine Flat Lake and south of Shaver Lake and Wishon Reservoir.

The cause of the fire remains under investigation.

Temperatures in the area of the Basin Fire are forecast to reach 113 degrees on Sunday and remain in triple digits throughout the week.

French Fire near Yosemite National Park

The French Fire near Yosemite National Park in Mariposa County has burned 908 acres since erupting Thursday and was 45% contained as of Sunday morning, according to CAL FIRE.

Three firefighters were injured battling the wildfire, which has destroyed four structures, CAL FIRE said.

McCain Fire in San Diego County

Another significant fire is the McCain Fire, which started on July 1 in southeast San Diego County.

As of Sunday, firefighters had the fire almost completely out, having achieved 95% containment on the blaze that has burned 1,595 acres.