A brutal heatwave enveloping the US west smashed records on Tuesday, as high temperatures and historic energy use strained California’s grid to the brink of its capacity and spurred fire behavior across the state.
Western states are struggling through one of the hottest and longest September heatwaves on record.
Temperatures began soaring last week and reached records in various parts of the region.
California’s state capital of Sacramento on Tuesday hit an all-time high of 116F (47C), breaking a 97-year-old record. Six places in the San Francisco Bay Area and central coast set all-time record maximum temperatures, including Santa Rosa, with 115F (46C).
In neighboring Nevada, Reno’s 106F (41C) on Tuesday was its hottest day ever recorded in September and smashed the previous record for the date, 96F (36C) in 1944. It came within two degrees of the all-time high for any day or month of 108F (42C), set in July 2002 and equaled in July 2007, according to the National Weather Service.
In Salt Lake City, at an elevation of more than 4,000ft (1,219 meters), temperatures were about 20 degrees higher than normal, hitting 105F (41C) on Tuesday, the hottest September day recorded going back to 1874. On Wednesday, Utah’s capital hit 107F (42C), tying for the all-time record.
The National Weather Service (NWS) warned that dangerous heat could continue through Friday.
In California, the grueling heatwave caused officials to warn on Tuesday that demand for electricity, some of it from people cranking up the air conditioning, might outstrip supply.
The California Independent System Operator (Caiso), which oversees the electrical grid, issued a stage three emergency power alert, one step below ordering utilities to start rotating outages to ease the strain on the system.
“This is an extraordinary heat event we are experiencing, and the efforts by consumers to lean in and reduce their energy use after 4pm are absolutely essential,” said Elliot Mainzer, the Caiso’s president and CEO in a written statement on Monday urging Californians to help shore up supply.
Just before 6pm on Tuesday, an energy emergency alert rang out on cellphones across California prompting an abrupt drop in usage as residents unplugged and conserved.
The grid was ultimately able to withstand this perilous stress test, even though the peak electricity demand hit 52,061 megawatts, far above the previous high of 50,270 megawatts set on 24 July 2006.
The story tomorrow should be, "what happened at 6:00 to save our asses?" My hunch is that's when the Cal OES alert went out on cell phones all over CA, and people were like "oh s***, turn off the lights!!!" pic.twitter.com/M5fnXn7qTC
— Kris Ankarlo (@KrisAnkarlo) September 7, 2022
Although there were no rolling blackouts over large areas, two outages were reported in the San Francisco Bay Area cities of Palo Alto and Alameda, affecting several thousand customers for about an hour.
Some 35,700 people lost electricity in Silicon Valley and southern and inland areas of the San Francisco Bay Area and most of the outages were heat-related, said Jason King of Pacific Gas & Electric (PG&E) said on Tuesday evening. There was no word on when power would be restored.
Meanwhile, the high temperatures fueled wildfires in both northern and southern California. Four deaths were reported over the Labor Day weekend as some 4,400 firefighters battled 14 large fires around the state, with 45 new blazes on Sunday alone, said Anale Burlew, a deputy chief with the California department of forestry and fire protection (Cal Fire).
A wildfire that started on Friday in the northern California community of Weed killed two people and one that erupted on Monday and spread rapidly in the Hemet area of southern California also killed two people. Authorities said they were found in the same area and apparently died while trying to flee the flames.
The Mosquito fire, a blaze that ignited on Tuesday night near Tahoe national forest exhibited extreme fire behavior and rapid spread, growing to more than 1,200 acres by Wednesday afternoon. Officials said “extreme burning conditions”, including spiking temperatures and low relative humidity were driving the fire. Evacuations were issued in Placer and El Dorado counties.
The escalation in fire activity seen across California this week may only be a hint of what’s to come in the months ahead.
“Extremely dangerous fire weather conditions are still expected today across the Northwest, including extremely critical dry/windy conditions and dry lightning with severe gusts,” the National Weather Service Storm Prediction Center tweeted on Wednesday morning.
Fire-risk in California mounts in the fall and officials are preparing for an escalation in the conditions that fuel them. Parched vegetation across the state is primed to burn, especially when the winds blow and the temperatures rise.
“What we see right now in the very beginning of fall and the end of summer is very typical for the state. The fuels are at their driest points,” said Jon Heggie, a Cal Fire battalion chief. “But with this extended heatwave that we are seeing statewide, it is resulting in fires with devastating effects.”
Scientists say climate change has made the west warmer and drier over the last three decades and will continue to make weather more extreme and wildfires more frequent and destructive. In the last five years, California has experienced the largest and most destructive fires in state history.
The climate crisis has also increased the likelihood of compounding catastrophes that test resilience and capacity to respond. Hurricane Kay, which is hovering near the Mexican coast, could cause thunderstorms in California.
There are risks of flooding in the southern part of the state and increased fire weather to the north.
“The concern would be dry or nearly dry lightning,” climate scientist Daniel Swain said during a Twitter Spaces event discussing the extreme conditions affecting California this week. “That would be a nightmare in the context of the unprecedented heatwave we’re currently experiencing, and just before autumn wind season.”
