“Dangerous heat” is expected from Friday through Labor Day, the National Weather Service warned on its website. In Orange County, a heat advisory warning will be in force in coastal areas from 10 a.m, Saturday until 8 p.m. Monday.
Woodland Hills is forecast to hit highs 115 degrees Sunday, when Antelope Valley cities will reach 111 and Saugus 112, according to the NWS.
The anticipated high temperatures are also sparking concerns about demand on the state’s power grid as residents turn up their air conditioning units.
The California Independent System Operator, which manages the power grid, announced that a Flex Alert — a call for voluntary conservation — will be in effect from 3 to 9 p.m. Saturday through Monday. Urging voluntary conservation is an effort to stave off to much strain on the state’s electrical system, possibly leading to rolling power outages, like those that occurred during high heat last month.
An excessive heat warning issued by the NWS will be in effect from 10 a.m. Friday until 8 p.m. Monday in the San Gabriel and Santa Monica mountains, Santa Catalina Island and the San Fernando, Santa Clarita, San Gabriel and Antelope valleys.
“Extreme heat will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities.” according to an NWS statement.
“Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors,” the NWS advised, adding that children, seniors and pets must never be left unattended in vehicles under any circumstances in since temperatures can quickly turn lethal in the current conditions.
“Take extra precautions if you work or spend time outside. 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.”
The weather service noted that the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments.
The high heat is being attributed to high pressure, which was centered near the California-Nevada border Wednesday evening and is forecast to settle into the Great Basin area through the weekend.
In forecasting an increased fire danger, forecasters said they were mainly focusing on the dryness that will take hold in the region, partly because of the absence of monsoonal moisture. NWS meteorologist David Sweet said humidity levels will fall to single digits in interior areas of L.A. County Thursday. But no red flag warnings indicating a high risk of wildfires are likely to be issued because there’s very little wind, if any.
The NWS forecast sunny skies in Orange County Thursday and highs of 74 in Laguna Beach and San Clemente; 75 in Newport Beach; 84 on Santiago Peak; 85 in Fullerton, Irvine and at Fremont Canyon; 86 on Ortega Highway at 2,600 feet; 87 in Yorba Linda, Anaheim and Mission Viejo; and 89 at Trabuco Canyon.
Coastal communities will climb up to 109 Saturday, about the same as inland communities, which is unusual.
By Wednesday, Mission Viejo will drop down to 90 degrees but all other locales will be in the 80s, except at the coast, which will have reverted to the high 70s, according to an extended NWS forecast.
Cooling centers will be open in several Orange County and Los Angeles County communities, and coronavirus policies are in place, they say.
Sunny skies were forecast in valley areas of L.A. County Thursday but partly cloudy conditions were expected nearer the coast, along with highs of 75 degrees at LAX; 80 in Avalon; 82 in Long Beach; 83 in Downtown L.A.; 90 in San Gabriel; 91 in Burbank; 92 in Pasadena; 97 in Saugus and Woodland Hills; and 102 in Palmdale and Lancaster. Temperatures will be up to eight degrees higher Friday, up to 11 degrees higher than that on Sunday, then begin a sharp decline, though by Wednesday several communities will still be in the 90s — 98 in the case of Woodland Hills.