Play Live Radio
Next Up:
Available On Air Stations
Watch Live


Mercury soars as late-summer heat wave bakes southern California

An outdoor thermometer shows the temperature well over 100 degrees at Cowles Mountain on June 10, 2019.
Kris Arciaga
An outdoor thermometer shows the temperature well over 100 degrees at Cowles Mountain on June 10, 2019.

Southern California will continue to bake under sweltering conditions that are expected to stretch through the Labor Day weekend — with excessive heat warnings kicking in or continuing Wednesday in parts of San Diego County.

The protracted heat wave began pushing up temperatures Tuesday, marking the onset of an expected weeklong period of oppressive conditions.

It's prompted calls for residents to take precautions against heat stroke and to conserve power whenever possible.


The extreme heat and low humidity could create elevated fire weather conditions as well, NWS forecasters said.

An excessive heat warning has been issued until 8 p.m. Monday for San Diego coastal areas and valleys. Temperatures expected to reach between 86 and 96 degrees in the coastal areas and between 97 and 105 degrees in the valleys.

The heat warning is in effect for Oceanside, Vista, Carlsbad, Encinitas, Chula Vista, National City, San Diego, Escondido, El Cajon, San Marcos, La Mesa, Santee and Poway.

The heat warning is also in effect in San Diego mountain communities with temperatures expected to reach between 89 and 99 degrees. It will be in effect in Julian and Pine Valley.

Temperatures rose a few degrees Monday and were spiking even more Tuesday — with more of the same in the forecast for Wednesday and beyond.


Resources to beat the heat

  • Click here for a list of Cool Zones in San Diego County or call 211 for information on the nearest near you.
  • People unable to get to a Cool Zone location without transportation assistance can call 211 to be connected to a transportation or rideshare service at no cost.
  • Seniors, people with disabilities or those on limited incomes can request a free electric fan from the county at no cost. Call 211 or fill out this survey to see if you're eligible.

"The abnormally long-duration heat wave remains on target. Excessive heat warnings will go into effect on Wednesday for all areas inland of the beaches, and last through Monday," the National Weather Service said.

The hot conditions are expected to peak Wednesday and Thursday, with temperatures as much as 10 degrees higher on Wednesday than on Tuesday in some areas, the NWS said.

After that, there will be only modest relief through the holiday weekend — if at all.

"The potential for Sunday and Monday being the hottest is still there, especially over the coasts and valleys," according to the NWS. "Valley temperatures will approach all-time records."

Forecasters said the heat will persist through Monday, with a high- pressure system finally weakening next Tuesday. But some valley areas will likely still have extreme heat into next week.

"Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors," the NWS urged. "Young children and pets should never be left unattended in vehicles under any circumstances."

Forecasters also urged residents to be aware of the signs of heat stroke and to take precautions.

"Take extra precautions if you work or spend time outside," according to the NWS. "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. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location."

Overnight lows will not offer much relief either, staying in the 70s and even in the low 80s in some of the hotter areas.

Meanwhile, the California Independent System Operator, which manages the state's power grid, noted that it has already issued a Restricted Maintenance Operations order that will take effect Wednesday and continue through next Tuesday — limiting maintenance operations between noon and 10 p.m. each day to ensure all power systems remain in service.

Cal-ISO warned that it may be issuing Flex Alerts, which are calls for voluntary power conservation during peak hours, generally between 4 and 9 p.m.