Historic, Prolonged Heat Wave Hits SoCal: Timeline For Peak Heat And The Cooldown

LOS ANGELES, CA — Winter in the Southland will end with another record-setting heat wave this week, in what forecasters warn will be a prolonged period of dangerous heat.

The National Weather Service issued a heat advisory for the most of Southern California from 10 a.m. Monday to 10 a.m. Tuesday, and an extreme heat warning from 10 a.m. Tuesday to 8 p.m. Friday. In San Bernardino and Riverside counties, an extreme heat watch advisory was issued.

Temperatures this week will be 20 to 35 degrees warmer than average, leading to many heat records potentially broken for the month of March. The National Weather Service said the heatwave will reach peak temperatures between Tuesday and Friday in Los Angeles, Orange, Riverside, San Bernardino and San Diego Counties.

"The heat event this week is forecast to be a historic March event, likely breaking many daily and even monthly temperature records," according to the National Weather Service. "There will be a high risk for heat illness for everyone — especially locations away from the coast. If you or someone you know is at risk for heat-related problems, please make cooling plans now for the rest of this week."

Forecasters said a very strong high pressure system will be lingering over the region through the week, keeping temperatures dangerously high.

On Monday, temperatures were predicted to reach into the 80s and mid- 90s across the area — roughly 15 to 30 degrees above normal for this time of year. By Tuesday and Wednesday, highs will reach into the mid-90s andlow-100s away from the coast, but the coasts will still be in the 80s and 90s.

Cal/OSHA urged employers to take precautions to protect workers as temperatures rise across the state.

"This is one of the first heat waves of the year, with temperatures rising above the seasonal average," the agency said in a statement. "Employees may not yet be acclimatized to high heat and may need additional breaks and interventions when they adapt to the conditions. Cal/OSHA reminds employers to be vigilant, especially with newer employees, and ensure that employees have shade, water and rest breaks to prevent heat illness."

The heatwave is expected to drop on Saturday with daytime high temperatures falling to 84 in Los Angeles County.

Warm overnight temperatures are also expected and could lead to heat risk, according to the National Weather Service.

The NWS warned the current heatwave carries a high risk for heat illness. Forecasters advised everyone to limit outdoor activity, seek air conditioning, drink plenty of hydrating fluids, and check in on neighbors and loved ones, between the hours of 10 a.m. and 8 p.m. on Monday.

City News Service contributed to this report.