An epic Southern California heat wave crested Sunday with numerous all-time high temperature records set, including a 121-degree reading in Woodland Hills that marked a historic milestone for Los Angeles County.
The broiling temperatures put extreme pressure on the power grid, with malfunctions leaving thousands without power and officials warning that rolling blackouts could affect millions of customers, although that threat eventually was averted.
It also fueled a series of fast-moving brush fires across the region, including one in Angeles National Forest near Duarte that broke out Sunday afternoon and forced Labor Day weekend visitors to flee.
In San Bernardino County, the El Dorado fire near Yucaipa had burned more than 3,000 acres and forced evacuations in some communities. To the south in San Diego County, the Valley fire in the backcountry had burned 5,300 acres and destroyed at least 10 structures.
The Woodland Hills reading of 121 degrees broke the county’s old record of 119 degrees set in July 2006 and was one of several records to fall Sunday. Escondido achieved an all-time high of 115 degrees, shattering a record set in 1909. Paso Robles also hit an all-time high at 117, as did Idyllwild (104) and Chino (121).
Woodland Hills is one of the hottest parts of Los Angeles and often records extreme temperatures. But Sunday’s conditions — measured at a station at Pierce College — marked the highest temperature from an official National Weather Service station in not only L.A. County but also Ventura, Santa Barbara and San Luis Obispo counties.
The weather service said Riverside hit its highest temperature ever for September at 117 degrees; Santa Ana hit a record high for the day at 106.
Officials have warned people to avoid outdoor activities even as temperatures cool slightly Monday.
A woman in her late 40s was hiking on a trail in the Santa Monica Mountains in Calabasas when she began to feel sick and collapsed at 2 p.m. Saturday, said L.A. County Sheriff’s Deputy Juanita Navarro.
She was pronounced dead at the scene. The official cause of death is still unknown, Navarro said.
Because of the dangerous heat wave, all trails in the Santa Monica Mountains are closed through Labor Day, Malibu Search and Rescue said in a tweet.
In Angeles National Forest, the Sheriff’s Department search and rescue team performed an air rescue Saturday on a semiconscious hiker suffering from heat exhaustion on the popular Strawberry Peak trail, where temperatures often soar because it has minimal shade in the afternoon.
The California Independent System Operator, which operates much of the state’s electrical system, had feared blackouts would be necessary during peak evening hours, but later Sunday night announced it had staved off the threat. The California ISO warned consumers they would be asked to limit electrical use Monday from 3 to 9 p.m.
The organization had declared a statewide emergency after a transmission line carrying power from Oregon to California and another in-state power plant went offline unexpectedly. The cause of the outages was unknown as of Sunday evening.
As of Sunday afternoon, much of Southern California Edison’s 18,000-plus reported outages were in Los Angeles County, where more than 10,000 customers were without power. The largest outages as of 2:30 p.m. Sunday included 1,203 in Inglewood and 1,126 in Paramount.
The outages were heat- or non-fire-related, said Edison spokesman Reggie Kumar, but overall, the electricity distribution system was performing well.
As of Sunday afternoon, the Los Angeles Department of Water and Power had enough power supplies and did not anticipate the need to implement rolling blackouts, a DWP spokesman said.
The utility did experience some small power outages in West Adams, Reseda, Sun Valley and Pacoima, among other places. As of Sunday morning, about 7,000 customers were without power, and crews had worked around the clock to restore power to 37,000 after temperatures and energy demand soared, according to the utility.
Pacific Gas & Electric Co. warned that the Diablo wind event set to hit Monday evening through midday Wednesday may require public safety power shutoffs for about 103,000 customers in the Sierra foothills, North Bay and East Bay. PG&E provides electricity across Northern and Central California.
The hot weather has hampered firefighting and heat-related rescue efforts across the state.
In the Sierra National Forest northeast of Fresno, the 45,500-acre Creek fire trapped more than 200 hikers in the Mammoth Pool recreation area when it crossed the San Joaquin River on Saturday afternoon, prompting a massive rescue effort by the California National Guard.
In Los Angeles County, the Bobcat fire started Sunday afternoon and quickly grew to 1,000 acres near the popular West Fork Picnic Area, a usually peaceful, wooded area where many residents fish and swim in the cool San Gabriel River.
California Department of Forestry and Fire Protection officials said Sunday evening that the El Dorado fire had a rather bizarre cause: a smoke-emitting device that was part of a gender-reveal party in a Yucaipa park. Such devices typically shoo off blue or pink smoke to signal the gender of an expected child.
“Cal Fire reminds the public that with the dry conditions and critical fire weather, it doesn’t take much to start a wildfire,” the agency said in a statement.
Hoist Rescue, hiker with heat exhaustion, Strawberry Peak Trail, Angeles Forest. #LASD Air Rescue 5 inserts LASD SEB Tactical Medics to rescue semi-conscious hiker. Airlifted to hospital. Very high temperatures today. Please do not hike without ample water supply. pic.twitter.com/ovfBhiRrKj
— SEB (@SEBLASD) September 5, 2020
Times staff writers Thomas Curwen in Los Angeles and Rong-Gong Lin II in San Francisco contributed to this report.