Heat wave spurs flex alert: What to know about this weekend’s weather

Customers cool off under a downtown mister in Palm Springs, where the temperature soared to 110 degrees.
Customers cool off under a downtown mister in Palm Springs, where the temperature soared to 110 degrees.
(Gina Ferazzi / Los Angeles Times)

Another heat wave is sweeping across Southern California this weekend, triggering a statewide flex alert and excessive heat warnings.

While flipping on the fan and pouring an iced drink, here’s what else to know about how to stay cool and safe during the withering weekend weather.

Record temperatures are expected for the region. They could be deadly, and they are a clear impact of climate change, scientists say.


Excessive heat warnings

Much of Southern California will be blanketed until Monday morning by excessive heat warnings for dangerously hot temperatures, some as high as 120 degrees, according to the National Weather Service.

Some of the areas likely to be hit hardest include the San Diego County deserts, the Coachella and Antelope valleys, interior San Luis Obispo County and the Cuyama Valley. Saturday will likely be the hottest day in this heat wave, forecasters said.

The Apple and Lucerne valleys could climb as high as 120 degrees by the weekend — potentially the hottest of the year so far.

And in Death Valley, the notoriously scorching desert, temperatures are expected to reach a blazing 130 degrees Sunday — tying a record for potentially the hottest on Earth in nearly a century.

The weather service also issued a heat advisory for the Santa Clarita Valley as well as the Los Angeles, Santa Barbara and Ventura County mountains, areas where temperatures could soar to 105 degrees.

Forecasters warn humidity is also expected to be low, around 10% to 13%. The combination of low humidity, high heat and gusty winds create an elevated fire risk.

The coastal parts of Southern California will predictably stay cooler, with temperatures likely below 80 degrees. But inland parts of Los Angeles County could push closer to 100 degrees, with desert temperatures likely to spike to 115.

Officials are calling on residents to cut back on their energy use from 4 p.m. to 9 p.m. on Friday in order to ease the strain on the grid.

Flex alert

The California Independent System Operator, which controls the state’s power grid, has issued a new flex alert for Friday, asking residents to voluntarily conserve electricity in the evening hours between 4 and 9 p.m., when power usage usually ramps up.

The grid operator issues a flex alert when extreme temperatures ramp up and it anticipates an energy shortfall.

To heed the flex alert, consumers should set thermostats at 78 degrees or higher, turn off all unnecessary lights and avoid using major appliances such as dishwashers or laundry machines until after 10 p.m. The grid operator also encourages using fans and unplugging other electrical appliances.

On Friday, Gov. Gavin Newsom signed an emergency proclamation to increase energy capacity amid the heat wave and the Bootleg fire in Oregon, which his office said are both impacting California’s power supply. It suspends certain requirements for thermal power plants and gives the state’s Air Resources Board discretion to permit the use of generators that reduce the strain on the energy grid.

Here are some ideas for reducing power usage and cooling down while California’s flex alert is in effect.

Staying cool

The weather service recommends people avoid doing strenuous activities outside and stay inside with air conditioning as much as possible. Drink plenty of water and wear lightweight clothing outside.

Officials warn that pets and small children should never be left unattended in vehicles, and residents should regularly check on neighbors and elderly people who may not have air conditioning.

Because of the evening flex alert, the grid operator recommends precooling the home by lowering the thermostat earlier in the day, close window coverings against the sun during the day and take advantage of solar powering appliances.

L.A. County Health Service suggests taking a couple of cool showers throughout the day and using sunscreen.

The county also offers several cooling centers, which can be found at