Southwest Heat

A lone hiker walks through Papago Park as temperatures hit 110 degrees Wednesday in Phoenix. Ross D. Franklin/Associated Press

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 begins to expand eastward. Nearly 60 million Americans are under heat advisories or excessive heat warnings.

A heat advisory covers almost the entirety of the states of Texas and Oklahoma and even extends into northwest Louisiana and parts of western Arkansas. Heat advisories and excessive heat warnings also cover 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.

What has been a dry heat in the Southwest will evolve into a more sultry nature east of the Rockies, as moist air is drawn north from the Gulf of Mexico. This will increase the risk of heat-related illnesses.

Early this week, cities from St. Louis to Charlotte will endure punishing heat with highs from 95 to 100 that will feel like 100 to 110 when factoring in oppressive humidity.

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, Texas: 102

San Antonio: 101

Albuquerque: 100

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

Houston: 98

Reno: 96 (tie with 1918)

Eureka, Calif.: 95

Flagstaff: 87 (tie with 1910)

In addition to all of these record highs, numerous locations in the region have 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.”

The worst of the heat on Saturday will concentrate from Texas to the Desert Southwest.

“The heat the past few days has already proven to be a major societal impact, and possibly even deadly, and it is not done yet,” the Weather Service office in Phoenix wrote.

Phoenix is forecast to hit 114, a record for the date; Las Vegas is predicted to reach 110, also a record.

Death Valley may match Friday’s high of 123, setting a record for a second straight day.

Abnormally hot weather has punished many parts of Texas since the second half of May and Saturday may be one of its hottest days yet. Forecast highs include:

Abilene: 107

Lubbock: 105

San Antonio and Austin: 104

Dallas: 103

Houston: 100

While it will be more of a dry heat in interior parts of Texas, humidity will increase nearer the Gulf Coast, making the heat even more dangerous.

“Heat safety will be critical this weekend – remaining hydrated, applying sunscreen, checking in on elderly or ill family and friends, and avoiding strenuous activity during the hottest parts of the day can all combat preventable heat-related illnesses,” wrote the Weather Service office in Houston.

It will also remain hot in California’s Central Valley, but several degrees cooler than Friday. Sacramento hit 104 on Friday; Saturday’s forecast high is 101. By Sunday, it’s a much more tolerable 85.

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, Illinois, Charlotte, and Columbia, South Carolina. Factoring in the humidity, it will feel 5 to 10 degrees hotter.

Tuesday’s hottest weather will focus from the Midwest to the Ohio Valley and Southeast with widespread mid-to-upper 90s – including Minneapolis, Des Moines, Chicago, St. Louis, Nashville, Cincinnati, Roanoke and Raleigh. Again, oppressive humidity levels will make it feel up to 10 degrees hotter.

Wednesday’s hottest weather will focus from the Midwest to the Ohio Valley, even expanding into the Great Lakes. Highs in the mid-to-upper 90s could reach Detroit, Ann Arbor, Michigan, and Cleveland.

While some relief from the heat will arrive in parts of the Midwest and Ohio Valley later in the week, the responsible zone of high pressure or heat dome will return to the Southern and Central United States into the weekend. In other words, there is no end in sight to anomalously high temperatures occupying considerable parts of the country.

Human-caused climate change is supercharging heat waves like this one, making them more intense and long-lived.

Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.