80M in U.S. under high heat alert

More than 80 million Americans remain under heat alerts as punishingly high temperatures keep their grip on the Lower 48 through the weekend.

Readings near or past 100 degrees stretch from the borders of Mexico to Canada on Friday. Over the next week, 85 percent of residents in the Lower 48 could experience temperatures of 90 or higher, with nearly 20 percent reaching or surpassing 100.

Heat advisories centered on Missouri cover parts of 13 states in the central and southern Plains into the midSouth. Additional advisories are up for much of the northeast urban corridor. Excessive heat warnings are also in effect Friday for 10 million people in the desert Southwest.

Washington, D.C., remains under a mayor-declared heat emergency through Monday. Pools in the city will be open late, while shelters and cooling centers are also available.

In Texas and much of the southern Plains, farmers and ranchers are struggling with scorched fields and stressed livestock. The persistence of hot and dry conditions is unheard of in parts of the region.

Dozens of record highs have already been breached in the past several days, and about three-dozen may be threatened through the weekend. Numerous records for warm lows are also likely.

An excessive heat warning is up for a big chunk of the desert Southwest on Friday, including the cities of Phoenix, Las Vegas, Nev., and Palm Springs, Calif.

“Well above normal high temperatures will likely top out at 110 to

115 degrees today for Phoenix and all lower desert communities across the region,” wrote the Weather Service.

This is on the heels of a number of record highs Thursday. They include Barstow, Calif., at 112; Bishop, Calif., 106; and Desert Rock, Nev., 108. A record high minimum of 90 was also tied in Las Vegas, Nev. In Needles, Calif., the overnight low was a remarkable 95 on Wednesday.

Friday is probably the last of this current bout of excessive heat for the region, as temperatures thereafter settle back toward normal levels nearer 100. Moisture associated with the summertime monsoon — a shift in winds bringing rain to the region — is slated to increase, helping build clouds and lower temperatures.

Across the Southern Plains and into the mid-South, 100-degree or higher temperatures have been the norm for weeks.

A slew of record highs fell across Texas on Thursday, including San Antonio, where it reached 102. It was the fifth record high there this month, on top of eight record highs in June and eight in May. The city has now seen 42 days at or above 100 in 2022, compared to an average of 19 for a whole summer.

Additional record highs Thursday included Houston (at Hobby Airport) with 100, Austin at 103 and College Station at 105.