Extreme heat breaking records from California to Texas

Scores of high-temperature records were established Friday from Texas to California’s Central Valley as a relentless heat wave continued to build. The heat is poised to expand into the Midwest and Southeast over the coming days.

On Friday, triple-digit highs set records in major population centers across the Southwest, including Houston, San Antonio, Austin, Albuquerque, Las Vegas and Phoenix.

The National Weather Service in Phoenix described the heat as “extreme and deadly.”

Many of these areas were forecast to be equally hot on Saturday, as the heat expands eastward. Nearly 60 million Americans were under heat advisories or excessive heat warnings.

A heat advisory covered almost the entirety of the states of Texas and Oklahoma and even extended into northwest Louisiana and parts of western Arkansas. Heat advisories and excessive heat warnings also covered parts of New Mexico, Arizona, Utah, Nevada and California.

By Sunday, the core of the heat is forecast to shift from California and the Southwest toward the Southern Plains. By Monday, it will ooze into the Central Plains and Midwest before reaching the Ohio Valley and Southeast on Tuesday and Wednesday.

Death Valley — home to highest temperatures ever observed worldwide — soared to a simmering 123 degrees Friday. That mark set a June 10 record and was the fourth earliest the mercury has climbed that high on record in the United States, according to Maximiliano Herrera, a climatologist who tracks world weather extremes.

Other record highs set Friday include:

• Phoenix: 113

• Las Vegas: 109

• Paso Robles, Calif.: 106

• Stockton, Calif.: 105

• Bishop, Calif.: 103

• Austin: 103

• Victoria: 102

• San Antonio: 101

• Albuquerque, N.M.: 100

• Grand Junction, Colo.: 100 (tie with 1981)

• Houston: 98

• Reno, Nev.: 96 (tie with 1918)

• Eureka, Calif.: 95

• Flagstaff, Ariz.: 87 (tie with 1910)

In addition to all of these record highs, numerous locations in the region set records for warm overnight lows. In Phoenix, it was still 100 degrees at midnight Saturday.

“With heat waves, the overnight temperatures are the most dangerous, as your body relies on cooler temperatures while its sleeping to recover,” wrote the National Weather Service office in Las Vegas in a forecast discussion. “Without this cooling, your body is less equipped to handle the scorching daytime heat, leading to increased incidences of heat exhaustion or heat stroke.”

While the heat gradually eases over California and the Southwest on Sunday and beyond, it will persist in Texas and the Southern Plains and expand eastward.

Sunday’s hottest weather will focus from Texas to Kansas with widespread triple-digit highs. Phoenix could top 110 degrees one more day, while eastern New Mexico and eastern Colorado will also swelter. Highs well into the 90s will expand across the Midwest, including St. Louis and Kansas City, and the Southeast.

Monday’s hottest weather will focus in the Plains and Midwest. Highs over 100 will expand from Texas

to Kansas, while highs from at least 95 to 100 sprawl over much of the Midwest and Southeast. St. Louis could hit 100 with upper 90s in Kansas City, Springfield, Ill., Charlotte, and Columbia, S.C. Factoring in the humidity, it will feel 5 to 10 degrees hotter.