California facing 'hottest and longest' heat wave on record, governor says

Record heat scorched parts of California on Tuesday, as power operators urged residents to cut back usage in the late afternoon to avoid rolling blackouts caused by high demand for air conditioning.

Among the highest temperatures expected on Tuesday was a record-setting 46 Cin the state capital of Sacramento, the National Weather Service said.

The heat wave, which began in Southern California last week and moved north over the Labour Day weekend, brought all-time high temperatures for Sept. 5 to San Francisco, Oakland, San Jose and other nearby cities, the National Weather Service said.

The hottest day of the heat wave was expected to be Tuesday, and California Gov. Gavin Newsom said the risk of power outages was real and immediate.

"This heat wave is on track to be both the hottest and longest on record in the state and many parts of the West for the month of September," Newsom said in a video sent to reporters.

In Livermore, about 64 kilometres east of San Francisco, temperatures hit 46.6 Con Monday, blasting through the previous high of 42.2 Cin 1950.

The California Independent System Operator, which manages much of the state's electrical grid, extended its call for residents to set thermostats to 25.5 Cand avoid using large appliances during the hours of 4 p.m. to 9 p.m. local time. During those peak hours, power generated by solar and hydro-electric resources begins to fade yet demand for air conditioning remains high as inland areas hit the hottest parts of their day.

Other power managers, including the Sacramento Municipal Utility District, asked residents of the hard-hit state capital region to conserve even more, setting their thermostats to about 26 C to help avoid blackouts. The heat, which is expected to continue through Friday, is leading to record demand on the energy grid, said Newsom.

More than two decades of drought and rising temperatures, exacerbated by climate change, have made California more vulnerable than ever to wildfires. The two most devastating years on record were in 2020 and 2021, based on the number of acres burned.

WATCH | Death Valley hits record-high 53 C:

California's Death Valley records temperature of 53 C during heat wave

2 years ago

Duration 1:28

Death Valley, Calif., recorded what may be a world record temperature for the month of September when the thermometer briefly hit 53 C (127 F) on Thursday.

The weather has also made it more difficult to fight wildfires, as hot air dries vegetation that can fuel blazes.

On Monday, a rapidly expanding wildfire in Riverside County, east of Los Angeles, killed two people and injured a third. On Tuesday, it was only fiveper cent contained, according to the California Department of Forestry and Fire Protection.

Over the past week, a fire in the far northern portion of the state killed two people and destroyed hundreds of homes and buildings in and around the city of Weed. As of Tuesday morning, that fire was 55 per cent contained after scorching some 1,620 hectares.