A high-pressure heat dome that sent temperatures skyrocketing along most of the western United States this week did not spare the Bay Area and California on Thursday, with temperatures rising into the triple digits as power grid operators asked Californians to conserve electricity for a second day.
“We’re seeing temperatures between 106 and 110 in Contra Costa County and 104 up in Santa Rosa,” David King, a meteorologist with the National Weather Service, said Thursday afternoon. “But the onshore winds are keeping the coast cool. It’s a stark difference — 60s on the coast in some places, and a 40-degree temperature swing inland.”
It was the hottest day of the year in many parts of the region, with more than half a dozen cities setting new records. According to the weather service, Livermore topped out at 107 degrees, eclipsing the previous high of 104 set in 1961; Gilroy hit 106, eclipsing the previous high of 105 set in 1961; Santa Rosa reached 104, toppling the previous high of 101 set in 1922; San Rafael, Kentfield and Redwood City climbed to 103, topping the previous highs of 99, 102 and 100 set in 1956, 1992 and 1945, respectively; and King City was at 101, edging out the previous high of 100 set in 1933.
Elsewhere, temperatures reached a searing 107 degrees in Concord, 95 in San Jose and 90 in Oakland, according to the weather service.
Lolita Peña waited out the hot midday sun Thursday afternoon at Seven Seas Park in Sunnyvale with her sons and two nephews. Caring for a 10-month-old baby, she said she hadn’t been able to spend much time cooling off in the water. By the time they got home, she said, she hoped it would be cooler.
“Oh my goodness,” she exclaimed, “It’s too hot! Bringing the boys to the park was one the best decisions we made today.”
Calling Thursday “the peak of potentially life-threatening hot temperatures” in Northern California’s inland communities, the National Weather Service issued an excessive heat warning lasting until 9 p.m. Friday for the East Bay Hills, North Bay Hills, San Benito County, Big Sur and the Salinas Valley. A more modest heat advisory remained in effect until 9 p.m. Friday for the Santa Clara Valley, Peninsula and Santa Cruz Mountains.
The California Independent System Operator, which oversees the state’s electric grid, extended its statewide Flex Alert to a second night on Friday. The ISO asked for electricity customers to conserve from 5 p.m. to 10 p.m. to reduce the risk of rotating blackouts when electricity demand soars. The ISO was “not anticipating rotating power outages,” officials there said, but asked for conservation in case wildfires took down power lines or mechanical breakdowns hampered power plants.
Residents were asked to keep thermostats at 78 degrees in the late afternoon and delay using appliances such as washers, dryers and dishwashers.
Gov. Gavin Newsom said the state power grid was in better shape this year than last, when blackouts occurred on two days in August during a similar heat wave for the first time in 19 years. He asked Californians to curb power use during the late afternoon.
“We just have to be a little bit more careful,” Newsom said during an appearance Thursday in Oakland to celebrate the reopening of small businesses. “We’ll get through the next few days.”
The governor declared a state of emergency Thursday afternoon, lifting some permitting rules and allowing wider generator and auxiliary-engine use. The moves would free up more energy capacity on the state’s grid but also increase air pollution.
Ultimately, no rotating power outages were needed Thursday, said Pacific Gas & Electric Co. in a tweet just before 10 p.m.
Cooled by ocean breezes, the coast was largely immune from the heat.
At 4 p.m. it was a balmy 63 degrees in Half Moon Bay, 66 in Pacific Grove and 67 at the Presidio in San Francisco.
With the heat across most of the region, however, and some smoke from fires in Arizona, the Bay Area Air Quality Management extended its Spare the Air Alert into Friday, warning residents of the dip in air quality that often comes with high pressure and high temperatures.
“Rather than getting back in your car, consider working remotely, taking transit, biking or walking to improve our air quality and help us all breathe easier,” said Jack Broadbent, executive officer of the air district.
The searing heat wave sent temperatures in the Central Valley up to 110 degrees Thursday and near 120 in Las Vegas and Phoenix. It came as a severe drought across the West continues to worsen. Overall, 85% of California is now in “extreme drought,” up from 2% a year ago, according to the U.S. Drought Monitor, a weekly report.
Heat waves and droughts are not uncommon across California and the West. They have occurred for centuries.
But climate change is making them worse. The Earth’s average global surface temperature has risen 2.16 degrees Fahrenheit since the late 19th century, largely due to climate change from the burning of fossil fuels, scientists say. The seven hottest years since 1880, when modern temperature records began, all have occurred since 2014, according to NASA.
“We expect more heat waves in a warmer climate,” said biologist Chris Field, director of Stanford University’s Woods Institute for the Environment. “For more than 30 years, many lines of evidence have pointed to the strong link between a warming climate and heat waves that are hotter, more frequent and longer.”
Relief will begin Friday, said King, of the weather service.
“Temperatures will start to go down,” he said. “But it is still going to be hot Friday. Then the cooling trend will continue into the weekend. By Sunday we’ll be back to normal — mostly 70s and 80s.”
Another wildfire threat was dry lightning, which some forecasts said could develop in the southern Sierra Nevada late Thursday and Friday. Dry lightning sparked hundreds of wildfires throughout the state last August.
At Cauldron Ice Cream in San Jose, Brandon Nguyen, 18, said business had almost doubled due to the heat. Kids clamored for ice cream, he said, and the store itself was a cool refuge, thanks to a powerful AC system.
“The environment is dying, but sales are going up,” he said.
Bay Area News group reporters Leo Castañeda, Kate Selig and Jason Green contributed to this story.
