Much of California and the Southwest will swelter under extreme heat on Thursday in a wave that's forecast to bring widespread record high temperatures.
Twenty-seven million people are under heat warnings and advisories today, as a heat dome essentially traps warm air from the Golden State down to southern Texas.
A major concern will be California’s Central Valley and the Desert Southwest “due to their lower elevations and some urban areas,” according to the National Weather Service. The heat will persist into the night — which “will affect those without effective cooling and/or adequate hydration.”
The record high temperatures are expected to hit New Mexico to California with highs soaring 10 to 25 degrees above average, impacting cities like Albuquerque, Las Vegas and Phoenix.
On Thursday, Phoenix is forecast to hit a whopping 113 degrees; Las Vegas may reach 112; and Death Valley, California, could be at 121 on amid the extreme heat wave.
By Friday, the heat wave will expand north into Oregon and Washington on Friday and Saturday, and ease Sunday across the Southwest.

Heat will also impact the Florida peninsula from Thursday into the weekend with several high and low temperature records forecast to be tied or broken from Jacksonville down to Tampa and Miami.
On Thursday, Miami has a forecast heat index of 105.
Meanwhile, on the East Coast, strong storms are possible along the I-95 corridor from Raleigh, North Carolina, to New York City. Strong storms will also be possible across eastern Florida and a small area of Texas and Oklahoma. The scorching temperatures are nothing new for parts of the Southwest.

Last summer, Phoenix saw a 31-day streak of above 110-degree weather from the last day of June through July. At least 400 of the year’s 645 heat-related deaths were during that period, The Associated Press reported.