A prolonged and prodigious heat wave continued to bake the Southland Thursday, and forecasters officially extended excessive heat warnings to confirm what was initially feared — the oppressive conditions will continue beyond Labor Day.
The change means at least one extra day of high temperatures that have already toppled some records and prompted statewide Flex Alerts calling for energy conservation to prevent strain on the state’s power grid.
“We are anticipating this extreme heat to be a length and duration the likes of which we haven’t experienced in some time,” Gov. Gavin Newsom said Wednesday. “Yes, we’re used to record-breaking temperatures, maybe a day or two, more episodic, but this is an extended period.”
The National Weather Service confirmed that prediction Thursday by extending excessive heat warnings for most of the region through 8 p.m. Tuesday. In the Antelope Valley, the warning will remain in place until 9 p.m. Wednesday.
The warnings were originally expected to expire Monday night.
“High pressure will persist over the area creating a prolonged period of very hot conditions with minimal coastal clouds,” the NWS said. “Triple digit heat is expected for many valley and mountain locations through early next week including coastal areas during the Sunday and Labor Day peak. This heat may be record breaking and will produce a very high risk of heat illness.”
The excessive heat warnings will be in effect until 8 p.m. Tuesday for the Los Angeles County Mountains, Santa Monica Mountains and the Santa Clarita, San Fernando and San Gabriel valleys, along with the inland coastal area, including downtown Los Angeles. Forecasters said temperatures in the mountain and valley areas could hit 112 degrees, while the inland coastal areas could hit 100.
The warning in the Antelope Valley will last until 9 p.m. Wednesday, with temperatures anticipated up to 113 degrees.
L.A. County beaches and the Malibu coast will be under a less-severe heat advisory from 10 a.m. Saturday through 8 p.m. Monday, but even along the coast the mercury could reach 92 degrees, according to the NWS.
In Orange County, excessive heat warnings were also extended through 8 p.m. Tuesday for coastal and inland areas and the Santa Ana Mountains and foothills. Forecasters said OC beaches will be in the 80s, with inland areas hitting the 90s, and possibly up to 105 farther from the coast in cities such as Anaheim, Garden Grove, Irvine and Fullerton.
“Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors,” the NWS urged. “Young children and pets should never be left unattended in vehicles under any circumstances.”
Forecasters also urged residents to be aware of the signs of heat stroke and to take precautions.
“Take extra precautions if you work or spend time outside,” according to the NWS. “When possible reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear lightweight and loose fitting clothing when possible. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location.”
Overnight lows will not offer much relief either, staying in the 70s and even in the low 80s in some of the hotter areas.
Several heat records were set on Wednesday. The mercury hit 112 degrees in Burbank on Wednesday, breaking the record for the date of 108 set in 2017. In fact, that temperature topped an all-time record for the month of August in Burbank. The previous high for the month was 111 degrees, set on Aug. 26, 1944.
Woodland Hills also reached 112 on Wednesday, breaking the Aug. 31 record of 111 set in 1998. Sandberg reached 100 degrees, besting the 2017 record of 98, while Lancaster tied the record of 109 degrees set in 1948, according to the NWS.
Anaheim reached 106 degrees, besting the Aug. 31 record set in 2007, and also beating the all-time record for the month of August, which was 105 degrees set on Aug. 18, 2020.
The California Independent System Operator, which manages the power grid, called for another Flex Alert on Thursday from 4 to 9 p.m. A Flex Alert was in place on Wednesday as well, for the same hours. The alert is a call for voluntary power conservation to lessen strain on the statewide electrical system.
More Flex Alerts are anticipated over the weekend, particularly on Sunday and Monday, which are forecast to have the highest electricity demand.
“With excessive heat in the forecast across much of the state and Western U.S., the grid operator is expecting high electricity demand, primarily from air conditioning use, and is calling for voluntary conservation steps to help balance supply and demand,” according to Cal-ISO.
During the alerts, residents are urged to take power-saving steps such as:
— setting thermostats to 78 degrees or higher;
— avoiding use of major appliances;
— turning off unnecessary lights; and
— avoid charging electric vehicles.
Residents are also advised to pre-cool their homes as much as possible, and close blinds and drapes to keep interiors cool.
Cooling centers for Los Angeles County can be found at ready.lacounty.gov/heat/. Cooling centers for the city of Los Angeles can be found at emergency.lacity.org/la-responds/beat-heat, or by calling 311.