Five things to know about the brutal California heat wave

Parts of California have been plagued by high temperatures since last week.

by Joseph Guzman | Sep. 07, 2022

Story at a glance

Much of California has been hit with triple-digit temperatures since the heat wave kicked off just before Labor Day weekend.

The severe September heat wave prompted state energy officials to call on residents to limit their electricity use to avoid rotating power outages.

Temperatures are forecast to remain well above average for many regions through Friday.

A brutal September heat wave continues to bake large parts of California, bringing record temperatures, threats of blackouts and increased risk of fire danger to the state plagued by drought.

Much of California has been hit with triple-digit temperatures since the heat wave kicked off just before Labor Day weekend, with a series of high-temperature records being broken in cities from California’s Bay Area to those south of Los Angeles.

The severe September heat wave prompted state energy officials to call on residents to limit their electricity use to avoid rotating power outages. California’s power grid operator issued an emergency alert Tuesday as the grid struggled to keep up with surging power demand, but said later in the evening that widespread blackouts were avoided across the state.

The heat wave was anticipated to peak Tuesday, but temperatures are now forecast to remain well above average for many regions through Friday.

Record-breaking heat

Long-standing daily and all-time records were shattered in cities across California over the past several days. Sacramento hit 116 degrees Fahrenheit for the first time ever, surpassing a 97-year-old record of 114 degrees previously set on July 17, 1925, according to the National Weather Service. Stockton reached 115 degrees, tying the city’s previous all-time record set in 2006. San Francisco was just a few degrees shy of breaking 100 degrees.

In the Bay Area, San Jose, Santa Rosa, Livermore, Redwood City, King City and Napa also experienced all-time record high temperatures. San Jose had a high of 109 degrees Tuesday, beating the old record of 108 degrees set in 2017. Santa Rosa hit 115 degrees, breaking a record set in 1913, and Napa had a high of 114 degrees. Both Livermore and King City reached 116 degrees.

In the Los Angeles area, both Burbank and Long Beach set daily records Sunday. Burbank hit 110 degrees while Long Beach Airport marked a high of 109 degrees. Newport Beach broke its all-time high temperature record of 96 degrees Sunday at 97 degrees.

Risk of power outages

California narrowly managed to avert rolling blackouts Tuesday as electricity use climbed and excessive heat taxed the state’s power supply.

The California Independent System Operator (ISO), the entity that oversees California’s electrical grid, warned there could be “rotating power outages” Tuesday evening as energy supplies appeared to be insufficient to “cover demand and reserves.” ISO reported statewide power demand hit 52,061 megawatts, a record for the state.

The ISO upgraded its Energy Emergency Alert level from 2 to 3, enabling the grid operator to order rotating power outages to lower demand and stabilize the grid if necessary. By 8 p.m. local time, ISO reported the alert level 3 had been lifted without any rotating power outages, due to Californians heeding the warning and conserving power. Residents were asked by utilities to keep thermostats at 78 degrees or higher and to avoid using major appliances or charging electric vehicles. Pacific Gas and Electric Company, a utility that provides power to large parts of Northern and Central California, warned some 525,000 customers of possible blackouts lasting 1 to 2 hours.

While no rotating blackouts were needed, tens of thousands of people found themselves without power in Northern California, including in Silicon Valley and southern and inland areas of the San Francisco Bay area. Most of the outages were heat-related. By Wednesday morning, about 20,000 people were without power, according to Power Outage.US.

As high temperatures are expected to continue through the next few days, the state is urging residents to continue conserving electricity. California has been under a statewide alert for energy conservation for more than a week.

“Thank you to everyone who saved power — coming together to keep the lights on for each other is the California way,” California Gov. Gavin Newsom’s (D) office tweeted Tuesday night.

“But, we aren’t out of the woods yet. We will see continued extreme temps this week and if we rallied today, we can do it again.”

Wildfire threat

As California’s power grid faces a major stress test, low humidity and high temperatures are increasing the risk for wildfires across the Golden State.

More than 4,000 firefighters are battling 14 large fires around the state, Anale Burlew, a deputy chief with the California Department of Forestry and Fire Protection said, according to The Associated Press. At least 45 new fires were started on Sunday alone.

The Fairview Fire in Riverside County in Southern California killed two people and left one injured. The blaze was sparked Monday and has burned about 5,000 acres, prompting evacuations. As of Wednesday the fire is just 5 percent contained, according to Cal Fire.

Hurricane Kay

A hurricane currently moving northward toward the Baja California Peninsula is expected to make the horrendous heat wave in Southern California worse.

Hurricane Kay is currently tracking along Mexico’s Pacific Coast and could bring heavy rain and flash flooding across the Baja California peninsula and parts of mainland northwestern Mexico through Saturday.

Hurricane conditions are expected along parts of the west-central Baja California coast on Thursday, and a hurricane warning is in place for that area.

The hurricane is forecast to come within 220 miles south of San Diego Friday and could bring easterly winds to the area, which is likely to prolong extreme heat the region has been dealing with for more than a week.

“It’s a complicated high temperature forecast for Friday for the coast and valleys,” the National Weather Service in San Diego said.

“Strengthening east winds between high pressure to the north and tropical system to the south bring downslope warming while moisture and clouds increasing from the south could offset the warming.”

The weather service in San Diego has extended its excessive heat warning for the region through Friday. The Los Angeles National Weather Service also expects dangerous heat to continue into Friday, with highs up to 95 along the coast and triple digits further inland.

More heat waves in the future

As it’s been a summer of record-setting heat across the U.S., severe heat waves like the one in California aren’t expected to slow down anytime soon.

Heat waves are occurring more often and with more intensity than they used to in major U.S. cities. The frequency of heat waves “has increased steadily, from an average of two per year during the 1960s to six per year during the 2010s and 2020s,” according to data from the Environmental Protection Agency (EPA).

The average duration of heat waves is currently about four days, about a day longer than the average heat wave in the sixties. California’s current heat wave will drag on for more than a week.

“Extreme heat events like the one currently facing California will absolutely continue in the future,” V. Kelly Turner, director of urban environment research at UCLA’s Luskin Center for Innovation, said in an email to Changing America.

“Climate projections predict more frequent and severe extreme heat events everywhere in the U.S., and longer heat seasons that stretch into the Fall. Some of this is ‘baked in’ to the future because of climate change. Cities and states will not be able to enact direction to change the weather. State and federal coordinated action on climate mitigation will be required to move the need on greenhouse gas reductions,” Turner said.

Just last month, a new heat model from the climate-focused nonprofit group First Street Foundation showed heat waves in California and most of the U.S. over the next three decades could be longer, hotter and more frequent.

The report found all areas of California will continue to see increases in the number of “Local Hot Days,” defined as days at or above the 98th percentile heat index temperature, over the next 30 years. Orange County will face the largest increase in hot days, with an estimated 22 days at or above 90.5 degrees Fahrenheit each year by 2053. Los Angeles County is expected to have 21 days per year exceeding 93 degrees by that time, while Imperial, Riverside and Fresno counties will also see significant increases in hot days.

Counties in Southern California are also expected to see a significant increase in the number of days with a heat index exceeding 100 degrees Fahrenheit. Imperial County, which currently has 102 days out of the year exceeding 100, is forecast to have 116 days with a heat index above 100 degrees by the 2050s.