California’s heat wave — one of the worst in state history — has entered day six, and while the state’s badly strained power grid escaped rolling blackouts Monday, it will be tested like never before Tuesday, officials warned. They are asking the public to ramp up conservation efforts or face the prospects of losing power, with energy use on Tuesday anticipated to be at record levels. In parts of the San Francisco Bay Area, temperatures could reach 117 or even 118 degrees.
The Chronicle’s weather team has been studying the models, and our newsroom meteorologists say that the oppressive heat will last through midweek.
Our reporters are fanning out today to bring you the latest news from around the state and the Bay Area.
Latest updates:
Sea breeze blowing in around S.F. Bay
The sea breeze was cranking up Tuesday afternoon around San Francisco Bay and the Sacramento-San Joaquin Delta, which potentially could bring some relief for areas of the East Bay baking in intense heat, according to Chronicle meteorologist Gerry Díaz. With south winds gusting to 25 mph in Napa, temperatures there dropped quickly, from 108 degrees at 1:45 p.m. down to 97 degrees at 2:35 p.m. If the breezes push east of the delta, Livermore, Vacaville and Fairfield could cool before peak heating hours Tuesday afternoon.
Mercury tops out at 94 degrees in downtown San Francisco
Temperatures in downtown San Francisco soared to 94 degrees Tuesday afternoon just before the cool sea breeze made it up and over Sutro Tower. The high for the official downtown S.F. site was five degrees warmer than Monday and just three degrees shy of the daily record of 97 degrees, set back in 2020. The city and much of the Bay area have been dealing with excessive heat for two days in a row — but the good news is that after today, the sea breeze will finally break through the heat dome and slowly bring temperatures down to average by the end of the week, according to Chronicle newsroom meteorologist Gerry Díaz.
San Francisco offering families free admission at most public pools to beat the heat
Most of San Francisco’s public pools will be free for select hours Tuesday and Wednesday, according to the city’s Recreation and Park Department. On Tuesday, Balboa Pool will be free from 2:30 p.m. to 4 p.m.; Coffman Pool from 3 p.m. to 4:30 p.m.; Martin Luther King Jr. Pool from 4 p.m. to 5:30 p.m.; Sava Pool from 2:30 p.m. to 5 p.m.; Rossi Pool from 2 p.m. to 3:30 p.m.; and Mission Community Pool from 2:30 p.m. to 3:45 p.m.
On Wednesday, Balboa will be free from 3:30 to 5 p.m.; Garfield Pool from 2:30 p.m. to 3:30 p.m. and 4 p.m. to 5 p.m.; MLK 4 p.m. to 5:30 p.m.; Rossi from 2 p.m. to 3:30 p.m.; and Mission from 2:30 p.m. to 3:45 p.m. Learn more about pool locations.
Power grid emergency acute: starting at 4 p.m. it’s at stage just before rolling blackouts
The risk of rolling blackouts in the late afternoon and early evening has become acute in California. By early afternoon power demand had already risen to nearly as high on Monday — even before peak demand hours formally begin. The power grid has declared a stage 2 emergency for the hours of 4 to 9 p.m. — if it gets to stage 3, rolling blackouts begin. It is not a good sign.
BART touts underground stations as cool-off spots
BART is encouraging Bay Area residents to escape the heat at Powell Station in S.F., which is underground. “Play some free arcade game at our station concourse, get lunch at Westfield (which is connected to Powell), enjoy the shade and AC,” the agency tweeted.
Previous record for power demand on grid could be smashed Tuesday
Heat forces closure of some Bay Area restaurants
From Livermore to San Francisco to Sonoma, restaurants throughout the Bay Area closed over the Labor Day weekend, and some may not reopen until the unbearable heat subsides. Read more here about restaurants’ struggles in the heat wave.
Oakland closes libraries without air conditioning
The Oakland Public Library temporarily closed four locations Tuesday that don’t have air conditioning and where the internal temperature exceeded 87 degrees, said library director Jamie Turbak. “We don’t have anywhere for staff to go to cool,” said Turbak. The four locations include the Melrose Branch, Elmhurt Branch, Temescal Branch and the Lakeview Branch. An additional five locations may close Tuesday if temperatures exceed 87 degrees by 3 p.m., she said. There are a total of 18 branches in Oakland. Here is a list of eight library branches that have air conditioning and double as cooling centers for residents during the heat wave.
Wine Country grape harvest affected
The hot weather is speeding up the grape harvest at many Bay Area vineyards, as high temperatures cause grapes to ripen sooner than they otherwise might have. Some winemakers are racing to get grapes off the vines so that they don’t shrivel into raisins, like Bruce Devlin at Ballentine Vineyards in St. Helena, who picked most of his fruit last week in anticipation of the heat spike. Others, like winemaker Laura Barrett at St. Helena’s Clif Family Vineyards, are waiting it out, hoping that the grapes can develop a little more flavor before they begin to dehydrate. “If we can manage to hold off until next week, that’s the best case scenario for us,” said Barrett. However, she’s remaining vigilant, and said she’ll expedite the picking schedule if she observes more raisining in the berries or scorching on the vine leaves.
BART says there are delays everywhere
“There may be up to 10-min delays today systemwide in all directions,” BART tweeted. “Trains will be traveling at reduced speeds in some areas due to warm weather conditions.” On the SFO-Antioch line, delays are up to 20 minutes because of the heat.
Newsom urges Californians to ‘double down’ on saving energy amid ‘real’ blackout risk
Gov. Gavin Newsom urged Californians to save energy during the state’s scheduled Flex Alert from 4 p.m. to 9 p.m. on Tuesday, to reduce strain on the power grid and prevent outages. “We’re heading into the worst part of this heat wave and the risk for outages is real and it’s immediate,” Newsom said in a video. He asked people to pre-cool their homes before 4 p.m., close their windows and blinds to keep their homes cool, avoid using large appliances and turn up their thermostats up to 78 degrees or higher after 4 p.m.
Spare the Air Alert extended through Wednesday
The Bay Area Air Quality Management District has extended its Spare the Air alert through Wednesday, with ozone hovering at levels that are moderate or unhealthy for sensitive groups in parts of the Bay Area. People are requested to limit driving where possible and be aware of the health effects of exposure.
Here’s how the Bay Area records break down
Besides Fairfield’s all-time Bay Area high of 117 degrees on Monday, records were broken at airport sites including SFO, San Jose and Livermore. The downtown Oakland station also broke a daily record. Extremely hot temperatures were observed in the East Bay, where Livermore broke its all-time record high by hitting 116 degrees.
Livermore, Vacaville both could hit or exceed 117 degrees
While Livermore was cooler than Vacaville in the early morning, it had caught up as of 11:30 a.m, when both cities were tied at 102 degrees. Both have a chance to peak at 117 or even 118. Fairfield is likely to run between 115-117 on Tuesday, according to Chronicle meteorologist Gerry Diaz.
State experiencing ‘worst’ September heat event on record, climate scientist says
The historic heat event baking California is set to become the “worst” heat wave on record for the month of September, climate scientist Daniel Swain said Tuesday. “By some metrics, it might be one of the worst heat waves on record, period, in any month given its duration and its extreme magnitude, especially in Northern California and especially in the Sacramento region,” Swain said on Twitter. The NWS Sacramento office predicted Tuesday’s temperatures could break all-time record highs. Downtown Sacramento could see a high of 115 degrees, two degrees higher than Monday, weather officials said. In the Bay Area, Vacaville could hit 117 degrees Tuesday, according to Chronicle meteorologist Gerry Diaz. Read more here about how the heat wave ranks in California history.
With a temperature of 111 degrees, a young woman cools off in the Russian River in Healdsburg, Calif., on Monday, Sept. 5, 2022.
Scott Strazzante / The Chronicle
Part of Northern California could be ‘even hotter’ on Tuesday
“Believe it or not, today could be *even hotter* than yesterday in some parts of NorCal,” UCLA weather and climate expert Daniel Swain tweeted. “Sacramento & adjacent areas now more likely than not to break all-time temp records in the 115-117F range. Many areas also saw record warm overnight temps last night.”
Stressed power grid declares first stage of emergency for the afternoon
The California grid operator pre-emptively declared an emergency for Tuesday afternoon and evening from 4 p.m. to 9 p.m., when air conditioning loads are high and demand peaks. The order, announcing the first of three levels of emergency, will free up additional resources to help supply and shave off demand. Californians are requested to reduce power use during that late afternoon/early evening period as much as possible. Rolling blackouts are a possibility if savings are insufficient, as the grid is expecting record demand amid the heat.
Fairfield reached record 117 on Monday as temperature report revised upward
Fairfield temperatures got as high as 117 on Monday, not 116, according to a revised report by the National Weather Service. 116 — the original number — was a new Bay Area record, and 117 becomes an even more dramatic Bay Area record. Vacaville could tie that number today.
All eyes on Vacaville
The Bay Area city most likely to hit 117 degrees on Tuesday is Vacaville, according to Chronicle meteorologist Gerry Diaz. Livermore and Fairfield will also be hot, but both were six degrees cooler than Vacaville as of 10:20 a.m. A delta breeze could knock a few degrees off Fairfield temperatures.
Bay Area all-time record could fall again today with 117 degree temperatures
Tuesday will be as hot, if not slightly hotter, than Monday. Chronicle meteorologist Gerry Diaz says more all time records are expected to fall. Livermore, Concord, Fairfield and Vacaville will be some of the Bay Area’s hottest spots and may contend with 116-117 degree temps this afternoon.
A man takes shelter from the sun as he waits for the bus in Oakland, Calif., on Monday, Sept. 5, 2022. Heat warnings and advisories have been extended until Thursday.
Santiago Mejia/The Chronicle
BART trains will continue running slower due to the heat
BART officials said Tuesday it will continue to run trains at slower speeds during the hottest hours of the day, according to spokesperson Chris Filippi. This slowdown may prompt delays on some trains.
Electricity-saving request in effect from 4 p.m. to 9 p.m. today:
Fire near Hemet in Southern California kills 2 people
Two people died and one person was injured in a wildfire that is rapidly spreading in Southern California, fire officials said Tuesday. The Fairview Fire in Riverside County sparked Monday about 4 p.m., prompting evacuation orders and warnings in the area, Cal Fire said. As of Tuesday morning, the blaze had grown to 2,400 acres and was 5% contained. The fire is burning east of Hemet, about an hour and a half east of Los Angeles. The cause of the fire was under investigation.
Baby rescued from hot car in Oakland
Oakland firefighters rescued an approximately 6-month-old baby who was locked in a car Sunday afternoon as temperatures reached 92 degrees, the Fire Department tweeted. “The baby is doing fine,” Oakland officials said. Officials urged people to never leave young children and pets unattended in vehicles at any time, but especially during a heat wave. According to the National Highway Traffic Safety Administration, 21 children have died this year after being left in hot vehicles.
Spare the Air alert extended
Burning Man ‘exodus’ leads to epic traffic jam
People leaving the annual Burning Man Festival in Nevada’s Black Rock desert north of Reno were stuck in an 9-hour traffic jam Monday as temperatures reached the triple digits, according to festival organizers. The festival’s “exodus” continued Tuesday morning, though it appeared traffic was running smoothly again, according to the Twitter account Burning Man Traffic.
Heat advisory issued for Bay Area coastline
The National Weather Service early Tuesday issued a heat advisory for the entire Bay Area coastline, from the Sonoma County coast to the Big Sur coast. The advisory will be in effect Tuesday 11 a.m. to 8 p.m. A previous heat advisory for interior parts of the Bay Area and surrounding region — such as Marin County’s coastal mountains, the San Francisco’s Bay shoreline and the Santa Cruz area — was upgraded Tuesday to an excessive heat warning, the NWS said. The excessive heat warning will downgrade back to a heat advisory on Wednesday and is expected to last through Thursday evening.
Bay Area school district cuts hours at three schools
Novato Unified School District will run a compressed schedule at Lu Sutton Elementary School, Novato High School and Hill Education Center, schools that have limited or no air-conditioning, during Marin County’s excessive heat warning from Tuesday to Friday. At the high school, each period will be shortened and the school day will finish by 1:15 p.m.
Storms possible next weekend
Tropical storm Kay is spinning off the southern coast of Baja California Sur, and is forecast to hit Baja as a hurricane by the middle of the week. Its remnants will bring plenty of moisture into Southern California. This moisture will help spawn scattered wet thunderstorms from San Diego to Santa Barbara, along with portions of Kern County and the Mojave, according to Chronicle meteorologist Gerry Diaz. The latest weather models are signaling that some of this remnant moisture will make it into NorCal next weekend as well. If enough moves in, Northern California could see wet storms as well. But if only sprinkles of remnant moisture move in, the chance for these storms producing dry lightning in the heat-strained forests of Northern California next weekend cannot be ruled out.
