On Wednesday, about 39 million people in the region were under heat alerts, according to the National Weather Service.

The season for pumpkin spice lattes is here. If you’re going to order one in California this week, you better get it iced, as the Golden State bakes in a heat wave. The hot weather comes as an area of high pressure over the eastern Pacific Ocean has nosed into California.

The month kicked off with triple-digit temperatures in many parts of the state, with millions of Californians under heat advisories through at least Thursday.

Down the California coast and across the southwestern U.S., a heat dome could allow temperatures to reach season-high records, AccuWeather meteorologists say. San Francisco, known for having temperate weather most of the year, could see the heat spike in the mid-90s, as a high pressure system traps warmth over a pocket of the western U.S.

The month kicked off with triple-digit temperatures in many parts of the state, with millions of Californians under heat advisories through at least Thursday.

Mother Nature has the heat cranked way up on the San Francisco Bay Area this week with a fall heat wave. Multiple records were broken on Tuesday for daily highs, the National Weather Service reported.

Triple-digit temperatures will hit California again during a fall heat wave, prompting additional evacuations, power shutoffs and increased fire risk.