Statewide Flex Alert issued during high heat in California, Gov. Newsom discusses temperatures

Southern California continued to bake Wednesday under sweltering conditions that are expected to stretch through the Labor Day weekend -- with excessive heat warnings in effect across the region. 

The California Independent System Operator has issued a statewide Flex Alert, a call for voluntary electricity conservation, for Wednesday from 4 p.m. to 9 p.m., due to high temperatures pushing up energy demand and tightening available power supplies.

Cal-ISO added in Southern California, temperatures are expected to be 10-18 degrees warmer than normal.

Gov. Gavin Newsom addressed the high temperatures Wednesday during a press conference. 

"Heat wave duration and intensity has never been more challenging," said Newsom. "So stay safe and hydrate." 

He encouraged residents to heed the call for conservation, noting that the most concerning days in terms of electricity demand will come on Sunday and Monday, during Labor Day weekend.

"Try not to use too much electricity in those key hours," he said. "... Try to reduce your consumption to the extent possible. If you're not home, it's a holiday weekend, Labor Day weekend, you're out enjoying yourself, we encourage you before you leave home if you can turn those thermostats up to 85 degrees, that would also help reduce demand."

The protracted heat wave began pushing up temperatures Tuesday, marking the onset of an expected weeklong period of oppressive conditions. 

The forecast has prompted calls for residents to take precautions against heat stroke and to conserve power whenever possible, with state officials warning of possible strain on California's electrical grid.

The extreme heat and low humidity could create elevated fire weather conditions as well, National Weather Service forecasters said.

During Flex Alerts, residents are urged to set thermostats to 78 degrees or higher, avoid using large appliances and turn off unnecessary lights.

"Lowering electricity use during that time will ease strain on the system, and prevent more drastic measures, including rotating power outages," according to Cal-ISO.