PG&E customers are being warned once again that power outages are "likely" on Tuesday afternoon and evening.
The utility company urged customers to conserve electricity from 3 to 10 p.m. and be prepared for disruptions that could last two hours.
The extended heat wave that has left the Bay Area and much of the state sweltering is blamed for the increased demand for power.
"The prolonged heat is expected to drive electricity demand higher, as nighttime temperatures are also forecast to be above average," PG&E said.
PG&E customers can find out when they may lose electricity in their home by entering their address here.
The statewide Flex Alert from the California Independent System Operator, which runs the state's power grid, is in effect until Wednesday night.
Over the weekend, California ISO ordered utilities to shed their power loads as demand for electricity to cool homes soared.
The first rolling blackouts in nearly 20 years came Friday as unusually hot weather overwhelmed the electrical grid. The three biggest utilities — Pacific Gas & Electric, Southern California Edison and San Diego Gas & Electric — turned off power to more than 410,000 homes and businesses for about an hour at a time until the emergency declaration ended 3 1/2 hours later.
A second but shorter outage hit Saturday evening, affecting more than 200,000 customers. Californians packed beaches and river banks over the weekend to cool off from scorching triple-digit temperatures that raised the risk of more wildfires and fears of the coronavirus spreading.
An irate Gov. Gavin Newsom signed an emergency proclamation Sunday allowing some energy users and utilities to tap backup energy sources. He acknowledged Monday that the state failed to predict and plan for the energy shortages.
“I am not pleased with what’s happened,” he said during a news briefing. “You shouldn’t be pleased with the moment that we’re in here in the state of California.”
Newsom also sent a letter demanding that the state Energy Commission, state Public Utilities Commission and the California Independent System Operator investigate the blackouts.