Electrical demand was much higher than normal for this time of year but no problems or shortages were expected on the state grid, said Gregg Fishman, spokesman for the California Independent System Operator, which controls about 80 percent of the grid.
"It's manageable. We've got the resources available," he said. Demand was expected to reach 46,000 megawatts, compared to 38,300 megawatts a year earlier, he said.
As Mother Nature served up California in a roasting pan, some people were able to seek relief at the beaches - though not in the hundreds of thousands who turned out over the weekend as the heat wave built.
"Because it's Monday and it's a school day, the crowd is a lot smaller, (but) it appears a lot of people aren't going to work or school," said Los Angeles County lifeguard Capt. Angus Alexander.
Angus said Monday was one of the best beach days of the year, with clear visibility all the way to Santa Catalina Island, the popular tourist destination about 20 miles off the mainland coast.
The city of Los Angeles urged people to use Parks and Recreation facilities, senior centers and libraries as cooling centers. A half-dozen senior sites were to remain open until 9 p.m., the Emergency Management Department said.
Umbrellas were the necessary accessory for many women venturing along sizzling sidewalks.
The National Weather Service said the siege of dry heat was being caused by a ridge of high pressure over the West that was keeping the Pacific Ocean's normal moist and cool influence at bay.
Firefighters were on alert for wildfires, but there was little wind amid the onslaught of dry heat.
Red Flag warnings for fire danger were posted in some areas, but mostly due to the withering effect on vegetation alone rather than the dangerous combination of low humidity and offshore winds. Air movement remained breezy at best rather than forming the gusty Santa Ana winds linked to destructive wildfires.
The early fall blast of intense heat follows an unusually cool summer that often found beaches covered in overcast and whipped by chilly winds.
"It's been a long time since we got this hot," said Seto, adding: "It's like our unexpected summer."