Power falters as region swelters

Triple-digit temperatures maintained a sweaty grip on Southern California on Sunday as the region was hit by scattered fires and power outages that cut electricity to thousands.

The continued sizzling heat, which brought some communities record temperatures, also made work more difficult for crews throughout the region battling four fires during the afternoon. By evening, the two largest of the weekend blazes continued to advance in the Angeles and San Bernardino national forests.

Round-the-clock demand for power knocked out transformers, depriving 23,000 homes of electricity throughout the region.

In parts of Los Angeles and the San Fernando Valley, 750 Department of Water and Power customers had endured 24 hours without lights, air-conditioning or working refrigerators. Sunday’s power use represented the highest demand the DWP has ever experienced for a Sunday in September, said spokesman Joe Ramallo. “We’re going to continue to see scattered outages,” he said. “We’ve got as many crews as we possibly can in the field.”

As of 7:30 p.m. Sunday, 21,000 Southern California Edison customers were waiting for the lights to come back on.

“What we need is a break in the weather to slow the pace in calls,” said Edison spokesman Steven Conroy.

Hardest-hit areas were Monrovia, San Gabriel, Covina, San Bernardino, Calabasas, Thousand Oaks, Moorpark, Temecula, Lake Elsinore, Yorba Linda, Fullerton, Long Beach, Lancaster, Rosamond and Lakewood.

The utility had 102 crews in the field, some of them working around the clock to replace transformers that overheated with days of unrelenting demand. Lightning hit some equipment over the weekend, and a small tornado Saturday knocked down 10 transmission poles.

“We’ve had just about everything happen over the last 24 hours and it’s complicated restoration efforts,” Conroy said.

Southern Californians flocked to beaches seeking relief from the heat, which is expected to moderate only slightly for today’s Labor Day holiday before more significant cooling begins around midweek.

Sunday’s heat “surprised us a little bit,” said Curt Kaplan, a meteorologist with the National Weather Service. He noted that temperatures in valley areas remained well above normal.

The sixth day of Southern California’s heat snap also brought higher temperatures in coastal areas that had stayed relatively cool recently. In Oxnard, the mercury rose to a high of 90, up from a high of 80 on Saturday, and Santa Monica recorded a high of 88, up from a peak of 84 the day before.

A record high for the date came in the Ventura County city of Camarillo, where the mercury rose to 94 degrees, breaking the previous mark of 93 set in 1955. Riverside also set a record, hitting 113 degrees, surpassing the high of 112 in 1948.

Los Angeles County’s highest temperatures came in the west San Fernando Valley, with Woodland Hills posting a high of 112. That was only two degrees below its record, and well above its normal high of 96 degrees for a Sept. 2. Nearby Chatsworth also posted 112 degrees, while Burbank hit 107 degrees.

Downtown Los Angeles reached 101 degrees, well shy of its record of 108, but still much higher than its norm of 84 degrees.

Compounding the heat problems, temperatures remained unusually high overnight, defying the typical Southern California pattern of significant cooling after sundown.

In Indio, for example, the overnight low dipped to just 89 degrees from 115, the hottest minimum ever recorded in the Coachella Valley community. The previous record, which came in 2003, was 89. Nearby Palm Springs chalked up a low of 87, surpassing the previous overnight low of 86, which was set in 2002.

Temperatures are forecast to edge down but remain unusually high for a couple more days, and could be 15 degrees lower in some areas by late in the week. “It will feel more like normal by Thursday and Friday,” Kaplan said.

A lightning strike during a thunder shower started a 22-acre brush fire Sunday afternoon in the Temescal Valley area of Riverside County just south of the 15 Freeway, forcing the evacuation of 30 homes and damaging four houses. It was contained within an hour by 140 firefighters aided by 25 engines, four air tankers and two helicopters.

Two homes sustained minor smoke damage in the Temescal Valley blaze. At another, dry leaves on the roof caught fire. Heat from the fire also blew out windows on a fourth house, said a public information officer for the California Department of Forestry and Fire Protection.

The biggest fire to break out Sunday was in the Angeles National Forest, about six miles southwest of Acton and south of California 14. The North fire was reported at 2:30 p.m. and by 9 p.m. had consumed 350 acres and remained out of control.

A contingent of 340 firefighters, aided by six air tankers and five helicopters, was dispatched to subdue the fire. Their efforts, however, were complicated by steep terrain, temperatures that reached 103 degrees and humidity in the 8% to 15% range.

No structures were threatened, and no injuries were reported.

The cause remained under investigation.

Lightning might have triggered the blaze, but it also is possible that a visitor to the national forest might have started it by violating the current ban on campfires, charcoal grills and smoking, authorities said. Those activities have been barred since Aug. 1, when the forest’s fire danger level was determined to be “extreme.”

A smaller fire, burning 85 acres, continued for a second day in the San Bernardino National Forest.

By Sunday evening, authorities said the Butler fire, which was sparked by lightning Saturday afternoon, was about 45% contained.

The blaze was about 2 1/2 miles west of Big Bear Lake dam, north of California 18, prompting the closing of portions of the road. Officials said they expected to keep the highway closed at least through Tuesday night.

Although the nearly 300 firefighters on the scene encountered steep terrain, they were aided by rains that helped douse the flames, said Kathy Johansson, a spokeswoman for the U.S. Forest Service.

No injuries were reported, and no structures were threatened.

In the Fairmont area of Lancaster, a lightning strike Sunday started a brush fire that burned 150 acres and had been 25% contained by Los Angeles County fire crews by the evening. No homes were threatened.

stuart.silverstein@latimes.com

bettina.boxall@latimes.com

deborah.schoch@latimes.com

Times staff writer David Haldane contributed to this report.