Southern California heat wave: Record-breaking March temperatures trigger health warnings
Scrambling to stay cool as LA is in heat advisory
FOX 11 spoke with spring breakers in town as Southern California was under a heat advisory.
LOS ANGELES - A significant early-season heat wave is gripping Southern California, pushing temperatures into the 90s across coastal and valley areas and threatening to shatter daily records by three degrees or more, according to the National Weather Service.
The unprecedented heat has forced the opening of cooling centers and triggered widespread health warnings just a week before the official start of spring.
What we know:
The National Weather Service (NWS) has issued a heat advisory effective through 8 p.m. Friday, with peak temperatures expected to hit between 90 and 100 degrees.
This "winter heat wave" is the result of a strong high-pressure system combined with a lack of cooling Pacific breezes—a phenomenon some meteorologists described as the "nation's air conditioner" being shut off.
In downtown Los Angeles, temperatures are forecasted to hit 93 degrees, while the San Fernando Valley could see 95 degrees.
Cal/OSHA and labor unions like the International Union of Bricklayers & Allied Craftworkers have activated safety protocols, including mandatory shade, electrolyte packets, and frequent breaks, specifically to protect workers who are not yet acclimatized to high heat.
By the numbers:
Temperatures are expected to reach historic highs for mid-March, with many areas seeing temperatures between 20 and 30 degrees above seasonal norms.
Below is a breakdown of the expected highs by county for Friday:
Los Angeles County
- Coast: 82° – 88°F
- Valleys/inland: 92° – 98°F
- Mountains/desert: 75°
Orange County
- Coast: 81° – 86°F
- Valleys/inland: 94° – 97°F
Riverside County
- Valleys/inland: 95° – 99°F
- Mountains/desert: 82°
San Bernardino County
- Valleys/inland: 93° – 98°F
- Mountains/desert: 76°F
Ventura County
- Coast: 78° – 84°F
- Valleys/inland: 90° – 96°F
- Mountains/desert: 72° – 80°F
Local perspective:
As temperatures are expected to soar amid a regional heat wave Thursday, the Los Angeles County Department of Public Health is warning people to avoid ocean waters at several beaches due to high bacteria levels.
The affected beach areas are:
- Santa Monica Canyon Creek at Will Rogers State Beach, near Will Rogers Tower 18, 100 yards up and down the coast from the creek;
- Santa Monica Pier, 100 yards up and down the coast from the pier;
- Pico-Kenter storm drain at Santa Monica Beach, near Santa Monica South Tower 20, 100 yards up and down the coast from the storm drain;
- Mothers Beach in Marina del Rey, entire swim area;
- Leo Carrillo State Beach in Malibu, 100 yards up and down the coast from the public restrooms;
- Pulga storm drain at Will Rogers State Beach, near Will Rogers Tower 5, 100 yards up and down the coast from the storm drain;
- Castlerock storm drain at Topanga County Beach, 100 yards up and down the coast from the storm drain;
- Escondido Creek at Escondido State Beach, 100 yards up and down the coast from the creek; and
- Marie Canyon storm drain at Puerco Beach, 100 yards up and down the coast from the storm drain.
Health officials said the warnings were issued after recent water samples showed bacteria levels exceeding state health standards, which could increase the risk of illness.
Meanwhile, warnings were lifted for the following beach areas where recent sample results identified water quality levels within state standards:
- Inner Cabrillo Beach in San Pedro; and
- Herondo Street storm drain in Hermosa Beach, near Hermosa Tower TK.
What we don't know:
While forecasters anticipate a cooling trend for Sunday’s Oscars ceremony, the specific intensity of the "stronger" heat wave predicted for next Tuesday remains subject to slight shifts in the high-pressure ridge.
Timeline:
Friday: Forecasted as the hottest day of the week, with inland areas sweltering.
Saturday: A temporary 5 to 10-degree cooling trend for coastal and valley areas.
Sunday: Temperatures begin climbing again into the 80s and low 90s.
Next Monday–Thursday: Significant warming resumes, with "excessive heat" possible by midweek.
What's next:
Temperatures will begin to creep upward again on Sunday, with most areas seeing a rise of 3 to 5 degrees, according to the NWS.
But as hot as this weekend will be, next week could be even hotter, with the NWS predicting "a large, long-lasting and dangerous heat wave — quite possibly one of the top heat wave events for the month of March, ever."
Monday's highs are expected to be in the 80s along the coast and into the mid-90s in the valleys. Tuesday will likely be the hottest day, with coasts ranging from the mid-80s to lower-90s and valley areas ranging from 95 to 102.
"Dangerously high" temperatures are expected to continue through Thursday. Maximum temperatures during next week's heat wave are expected to be 20 to 30 degrees above normal, forecasters said.
The NWS issued an extreme heat watch that will be in effect from Monday through Friday, warning again that a "historic, long and record-breaking March heat wave" is possible.
What you can do:
- Hydrate: Drink plenty of fluids even if you don't feel thirsty.
- Limit Activity: Schedule strenuous outdoor tasks for the early morning or late evening.
- Check-In: Visit elderly relatives or neighbors who may not have adequate cooling at home.
- Safety First: Never leave children or pets in a locked vehicle, as interior temperatures can become fatal in minutes.
The Source: This report is based on information from the National Weather Service. The Associated Press and City News Service contributed.