SAN FRANCISCO - California's Independent System Operator has issued a statewide flex alert for Thursday June 17 from 5 p.m. to 10 p.m.
Cal ISO issued the voluntary call to conserve energy Wednesday afternoon as temperatures in the Bay Area soared in the first heat wave of the season and record breaking heat blankets the West Coast this week.
By Wednesday, Fairfield reached triple digits. Many other spots in the East Bay, including Fremont, Walnut Creek and Concord are already getting close as the mercury rises. The heat is expected to peak on Thursday, with an excessive heat warning in effect through Friday night for many areas throughout the Bay.
"If demand still outstrips supply after Flex Alerts and other measures are taken, the ISO could again order utilities to begin rotating power outages. That would extend available power supplies and guard against longer and more extensive disruptions while protecting high-voltage transmission lines from damage," a Cal ISO statement read Wednesday evening.
Earlier in the day, Cal ISO said the grid is stable for Wednesday and there was no expectation of rotating power outages. Forecasts also show enough reserves to cover demand Thursday evening, but the grid operator had warned to be vigilant for a flex alert.
It asks Californians to set thermostats to 78 degrees or higher, turn off unnecessary lights, unplug unused items, and avoid use of major appliances.
For more information on ways to conserve energy during the flex alert check here.
Flex alerts are typically issued as solar energy production drops off during evening hours.
Summerlike heat arrived with spring still on the calendar as a dome of high pressure spread over the West.
Cooling centers are available in parts of the Bay Area.
Associated Press contributed to this story.