The ocean breeze that has long made Santa Monica a refuge from Southern California's inland heat is offering little protection this week, as an extreme heat wave grips the region and pushes temperatures in the beach city well above normal.
The National Weather Service issued an Extreme Heat Warning for Santa Monica beginning at 10 a.m. Tuesday and continuing through 8 p.m. Friday, part of a broader warning covering much of Los Angeles County, including the Malibu Coast, Los Angeles County beaches and the Santa Monica Mountains. The warning signals dangerously hot weather that creates a high risk of heat-related illness for everyone, not just those in the region's usually sweltering inland valleys.
While Southern California's coastline typically offers a natural buffer against the kind of triple-digit heat that bakes the San Fernando and Antelope valleys, forecasters say that buffer will be thin this week. According to the National Weather Service's area forecast discussion issued early Tuesday from the Los Angeles/Oxnard office, a strong and expansive upper-level high pressure system is settling over New Mexico and Arizona, producing weak onshore breezes and even offshore flow during some mornings. The marine layer will be shallow and will not extend far inland, according to the forecast discussion, meaning less of the marine air that normally cools coastal communities like Santa Monica.
The Los Angeles County Fire Department said coastal areas, including Santa Monica, should expect highs between 80 and 90 degrees through Friday, while inland and inland-adjacent areas could see 90 to 100 degrees and valleys and lower mountain elevations could reach 100 to 110 degrees. The forecast discussion noted that without a strong onshore push in the afternoons, inland portions of coastal regions could warm into the 90s, with some spots reaching 100 to 101 degrees.
Nighttime offers little relief. The forecast discussion said overnight lows will run 6 to 12 degrees above normal as an inversion sets up near valley and foothill elevations, meaning even after sunset, residents may not get the cooling they are used to.
Tuesday through Thursday will mark the peak of the heat event, forecasters said, with only slight relief arriving by Friday. A more meaningful cooldown is expected over the weekend as a trough moves in from the west, but the National Weather Service and Fire Department warned that all heat warnings and advisories now in place will remain in effect until then.
Health officials are urging residents, even those in typically temperate coastal communities, not to let their guard down. The Los Angeles County Department of Public Health said the extreme heat "creates a high risk of heat-related illness for everyone" and urged residents to check conditions using the National Weather Service's HeatRisk map, which factors in how unusual the heat is for the time of year, its duration and social vulnerability data from the Centers for Disease Control and Prevention.
"Heat causes more deaths in the U.S. annually than floods, storms, and lightning combined," Dr. Muntu Davis, the Los Angeles County health officer, said in a statement. He said older adults, young children, outdoor workers, athletes and people with chronic medical conditions are most likely to become ill during the heat wave and urged anyone experiencing dizziness, nausea, a rapid heartbeat, confusion or fainting to seek medical help immediately.
Public health officials said residents should call 911 immediately if they or someone nearby shows signs of heat-related illness, including a body temperature of 103 degrees or higher, hot and red or dry skin, a fast and strong pulse, confusion, dizziness, nausea or fainting.
Officials recommended drinking water throughout the day even without feeling thirsty, avoiding outdoor activity during peak heat hours, wearing lightweight and light-colored clothing, and using sunscreen of SPF 15 or higher. Residents without air conditioning were urged to visit a cooling center, library, shopping mall or other air-conditioned space, or to call 211 for help locating one. In Santa Monica, public libraries are being offered as cooling locations, according to a public alert from the National Weather Service, which pointed residents to santamonica.gov/library-locations-and-hours.
Officials also stressed that children and pets should never be left in vehicles, even briefly, warning that interior car temperatures can climb dangerously even with windows partially open.
Beyond the health risks, the heat wave is elevating the danger of wildfire across the region. The Fire Department said it is augmenting staffing and pre-positioning personnel and equipment countywide to ensure a rapid response to fires. The National Weather Service forecast discussion said the combination of triple-digit heat, deep mixing heights, gusty winds, low humidity and fuels approaching critical dryness will raise the risk of large, plume-dominated fires with rapid spread in interior mountains and adjacent foothills across Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties, prompting a Red Flag Warning from Tuesday through Friday. The discussion cited the historical precedent of large fires under similar conditions, including the Bridge, Bobcat and Station fires.
The Fire Department urged residents to sign up for emergency alerts at alert.lacounty.gov, to have a wildfire evacuation plan in place through the county's Ready! Set! Go! program, and to immediately report any sign of smoke or fire by calling 911.
The heat wave also is expected to bring hazardous ocean conditions. The Fire Department warned of elevated surf and strong rip currents that raise the risk of ocean drownings, advising beachgoers to check with lifeguards on conditions before entering the water.
County officials said additional information is available at ready.lacounty.gov/heat or by calling 211, which operates 24 hours a day, seven days a week.