California heatwave: Bay Area set for hottest day ever with some areas forecast to reach 120F

·6-min read
California heatwave: Bay Area set for hottest day ever with some areas forecast to reach 120F

Record-breaking heat smashed through California over the Labor Day weekend, pushing temperatures to extremes and spreading anxiety over potential blackouts.

And things are only getting hotter in part of the state. Temperatures are forecast to reach up to 120 degrees Fahrenheit (49 degrees Celsius) in parts of the Bay Area on Tuesday.

That would absolutely shatter the Bay Area’s previous temperature record of 116F (47C) — which was just set on Monday.

Meteorologist Colin McCarthy said on Twitter that Tuesday is set to be “the hottest day ever recorded in the San Francisco Bay Area and Sacramento regions.”

Temperatures in Sacramento and Stockton are forecast to reach 115F (46C) on Tuesday. Other parts of the Central Valley, from Redding down to Bakersfield, are all set to reach highs of at least 110F (43C).

Even the cool and temperate coastal regions of northern California are expected to reach well above normal on Tuesday. Downtown San Francisco is forecast to reach up to 90F (32C) and Santa Cruz is forecast to reach up to 99F (37C).

North of the Bay Area, the area around Ukiah, California could see heat hit up to 117F (47C).

Southern California’s heat will also continue on Tuesday, with highs up to 115F (46C) in the Coachella Valley, 109F (43C) in the San Fernando Valley and 96F (36C) in downtown Los Angeles.

Officials have warned that with such extreme temperatures comes a serious risk of blackouts as energy demands soar, in large part due to air conditioning needs.

Residents were able to stave off widespread outages on Monday, but the electricity grid operator in the state, California ISO, has warned that energy demands on Tuesday are forecast to reach all-time record levels as people return to the office and air conditioners stay high amid brutal heat.

Demand is forecast to reach 51,145 megawatts — and California ISO projects that the grid will run between 400 to 3,400 below demand.

A “Flex Alert” has been issued for Tuesday during the peak demand hours of 4 PM to 9 PM. During those times, residents are encouraged to refrain from using major appliances or charging electric vehicles and set thermostats to 78F (26C) or higher.

California ISO also issued a Stage 2 Emergency Energy Alert on Monday, which prompts further emergency actions to boost electricity supplies. A Stage 3 alert would mean rolling blackouts to conserve electricity in a last-ditch scenario.

On Monday, the state activated some emergency power generators for the first time to boost energy supplies. Rolling blackouts last hit California during a heatwave in August 2020.

Nearly 18,000 customers were without power on Tuesday morning due to scattered outages across the state, according to, leaving people potentially exposed to dangerous heat without cooling.

Some of these outages in the Bay Area were caused by transformer failures due to the extreme heat, reports the San Francisco Chronicle.

California Governor Gavin Newsom declared a state of emergency last week in response to the heatwave, with emergency measures to boost electricity supplies.

Almost the entire state of California, as well as parts of Nevada and Arizona, is under an “excessive heat warning”, with the National Weather Service (NWS) warning of potentially dangerous conditions.

Across the country, more than 55,000 people are under some kind of extreme heat warning.

Extreme heat like this can cause heat-related illnesses, ranging from heat rash to potentially fatal heat stroke, where the body is unable to cool itself down. NWS encourages people to stay hydrated, seek air conditioning and check up on people who are especially vulnerable to heat, like the elderly and those with pre-existing health conditions.

Cooling centres have been opened across the state for people who don’t have access to air conditioning.

The heat has also sparked wildfires across the state. Over the weekend, firefighters battled 14 large fires — with more than 40 new fires starting just on Sunday, according to the Associated Press.

Two people were killed on Monday in the Fairview Fire in southern California’s Riverside County. Another two people, women aged 66 and 73, have been killed in the Mill Fire in northern California.

The fires have been exacerbated by the ongoing drought in the state, part of the decades-long “megadrought” in the western US. One recent study found that the megadrought, fuelled by the climate crisis, has been the driest 22-year period in the region for at least 1,200 years.

The heatwave is set to abate by the end of the week. Though, these kinds of extreme heat events are likely to become a lot more common.

If the planet reaches 2C of warming above 19th-century temperatures, heatwaves that once occurred every 10 years would happen about every other year, according to the United Nations’ Intergovernmental Panel on Climate Change, the leading authority on global climate science. Those heatwaves would also get about 2.6C hotter.

Already, the planet has warmed about 1.1-1.2C above 19th-century temperatures, and is on track to reach 2.7C of warming by the end of the century, according to the Climate Action Tracker, an independent analysis of global climate policy.