A brutal heatwave enveloping the US west smashed records on Tuesday, as high temperatures brought California to the verge of ordering rolling blackouts.
Western states are struggling through one of the hottest and longest September heatwaves on record. Temperatures began soaring last week and the National Weather Service (NWS) warned that dangerous heat could continue through Friday.
California’s state capital of Sacramento on Tuesday hit an all-time high of 116F (46.7C), 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 (35.5C) 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, a city at more than 4,000ft (1,219m) elevation, temperatures were about 20 degrees higher than normal, hitting 105F (40.5C) on Tuesday, the hottest September day recorded going back to 1874.
The grueling heatwave caused California 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.
But the grid managed to handle record-breaking demand. Caiso said the peak electricity demand on Tuesday hit 52,061 megawatts, far above the previous high of 50,270 megawatts set on 24 July 2006.
While 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 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 extreme temperatures are a result of a “heat dome” bearing over the region – a ridge of high atmospheric pressure that acts as a lid, trapping in heat. Although climate crisis doesn’t cause heat domes, scientists expect it to drive more extreme weather.
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.