Southland residents will get one more day of relatively milder weather Wednesday before temperatures begin climbing Thursday, with dangerous heat expected to peak over the weekend.
Wednesday’s temperatures are expected to remain only a few degrees above average before a strengthening high-pressure system expands westward, according to the National Weather Service.
Widespread moderate to high heat risk is expected Friday through the weekend, when temperatures are forecast to climb into the mid-90s to 105 degrees across most inland communities.
“The heat is expected to peak on Saturday with high temperatures for inland areas 10 to 15 degrees above average, near record setting for the lower deserts and portions of the mountains,” according to the NWS.
The weather service issued an extreme heat warning that will be in effect from 10 a.m. Thursday through 8 p.m. Sunday for the Antelope Valley and Antelope Valley Foothills, where temperatures of 105 to 115 degrees are possible.
In the western San Gabriel Mountains and the 5 and 14 Freeway corridors, a heat advisory will take effect at 10 a.m. Thursday, with triple-digit temperatures anticipated, but it will be replaced by a more severe extreme heat warning at 10 a.m. Friday through 8 p.m. Sunday, when highs are expected to range between 95 and 105 degrees.
An extreme heat warning will also be in effect from 10 a.m. Friday through 8 p.m. Sunday for the Santa Monica Mountains Recreational Area, Calabasas, Agoura Hills, the San Fernando and San Gabriel valleys and the Los Angeles inland coastal area, including downtown. Those areas could see “dangerously hot conditions” with temperatures of 95 to 110 degrees, according to the NWS.
The eastern San Gabriel Mountains will be under a heat advisory starting at 10 a.m. Thursday and continuing through 8 p.m. Sunday, while Los Angeles County beaches, the Malibu coast and Palos Verdes Hills will be under a heat advisory from 10 a.m. Friday through 8 p.m. Sunday. All of those areas could see temperatures as high as 100 degrees, forecasters said.
In Orange County, temperatures are expected to remain only a few degrees above average Wednesday before warming begins Thursday. Forecasters said the hottest conditions are expected Saturday, with Anaheim forecast to reach 92 degrees Friday and 95 Saturday.
An extreme heat warning will be in effect from 10 a.m. Friday through 8 p.m. Sunday in the Santa Ana Mountains and foothills, with temperatures up to 103 possible, and in Orange County inland areas, which could have temperatures in the upper 90s. A less severe heat advisory will impact Orange County coastal areas from 10 a.m. Friday through 8 p.m. Sunday, with highs expected in the mid-80s to lower 90s.
The weather service also warned that hot, unstable conditions and pockets of gusty winds could elevate the risk of large wildfires heading into the weekend.
“High temperatures will begin to cool a few degrees for Sunday and Monday, but still be around 10 degrees above average for inland areas on Monday with extreme Heat Risk for the deserts,” the NWS said.
The Los Angeles County Department of Public Health urged residents to take precautions, warning that prolonged high temperatures and warm overnight conditions increase the risk of heat-related illness.
“Heat causes more deaths in the U.S. annually than floods, storms and lightning combined,” Los Angeles County Health Officer Dr. Muntu Davis said. “If you or someone around you experiences symptoms of heat stroke or heat exhaustion, such as dizziness, nausea, rapid heartbeat, confusion or passing out, seek medical help immediately.”
Public health officials urged residents to stay hydrated, limit outdoor activity during the hottest part of the day, seek air-conditioned spaces if their homes become too warm and check on older adults, children and others at greater risk of heat-related illness. Officials also reminded residents never to leave children or pets unattended in vehicles, even for a short time.