Excessive heat: Temperatures over 100 swelling from Texas to California

Temperatures are soaring from Texas to California this week with readings topping 110 degrees in some areas and an escalating danger of heat-related illnesses. The National Weather Service is calling the heat “dangerous,” “extreme” and “excessive,” warning vulnerable populations to take steps to ensure access to cooling resources.

The heat is predicted to peak on Friday with the potential for dozens of records highs hotter over 100 degrees. Already, temperatures as high as 117 degrees have scorched Texas while they could top 120 degrees in Death Valley, California, on Friday.

By early next week, the heat will abate some in parts of the Southwest and Texas while shifting toward the Southeast. The relief from the heat in the Southwest will come at the cost of increasingly gusty winds, which could bolster the risk of rapid fire spread.

The sizzling temperatures mark the start of the hottest time of year in the Desert Southwest, which usually persists through at least June before the summer monsoon kicks in and sometimes brings cooling clouds and storm chances.

In addition to Texas and the Southwest, extreme heat is also forecast to spread into California’s Central Valley from Redding to Bakersfield, which are under excessive-heat watches late this week.

In Texas, several record highs were set on Tuesday, with most extreme heat focused west of Interstate 35, especially southwest of Midland across the Davis Mountains, Marfa Plateau and Big Bend areas. At Rio Grand Village, in Texas’ Big Bend area near the border with Mexico, the mercury surged to 117 degrees, just three degrees below the highest temperature ever observed in the state.

Some of Tuesday’s record highs included 103 degrees in Austin and 104 in San Antonio.

Midland topped 100 degrees for the 13th time in 2022, more than twice as many times as in 2021.

Little change in the scorching weather pattern is expected for days over the Lone Star State. Most of central, south and west Texas will sit near or just above the century mark through at least early next week. Numerous additional record highs are predicted each day.

The heat focused over Texas in now expanding westward.

The National Weather Service has plastered much of southeast California, southern Nevada and southern Arizona with excessive heat warnings. That’s where the hottest weather will occur between Thursday and Sunday.

The Phoenix area is under an excessive heat warning through Monday. The city is forecast to hit 106 to 110 degrees on Wednesday and Thursday before lurching to 112 on Friday and 113 on Saturday. Friday’s high should set a record, beating out the 111-degree reading in 1978. Records in Phoenix date from 1895.

“Stay indoors and seek air-conditioned buildings,” wrote the National Weather Service in Phoenix. “Drink water, more than usual, and avoid dehydrating alcoholic, sugary, or caffeinated drinks.”

They agency also included a list of signs and symptoms of heat stroke in its bulletin, warning “Heat stroke can be DEADLY. Treat as an emergency and call 911.”

In Yuma, Ariz., along the Colorado River on the California-Arizona border, both weekend days should peak around 112 degrees. Yuma is such a hot place that records will not be in jeopardy.

Death Valley – home to the highest temperature measured on the planet – is forecast to see highs exceeding 120 degrees Friday and Saturday – near records for the time of year.

Las Vegas could also challenge records Friday and Saturday, with highs around 110 degrees.

Throughout the Southwest, overnight lows – which will be hard-pressed to dip below 80 degrees – will be potentially most hazardous.

Most residences in this part of the country are equipped with air conditioning, but in places where that’s not the case or for those who are homeless, warm overnight lows can make it tough for the human body to cool down. Older adults and other vulnerable populations can suffer disproportionately because of the added stress on their bodies.

The punishing heat will arrive in California’s Central Valley starting Thursday and peaking Friday, when the zone from Bakersfield to Redding will endure highs in the triple digits. An excessive heat watch is in effect over much of this zone and multiple record highs are projected on Friday.

Forecast highs on Friday include 102 degrees in Redding, 105 in Chico, Sacramento and Fresno, and 103 in Bakersfield.

The excessive heat will not last terribly long in the Central Valley, with highs returning to near 90 Sunday into early next week.

The overarching weather pattern is boosting the odds of record-challenging heat, with a ridge of high pressure cresting overhead by the weekend.

Strong high-pressure systems, commonly referred to as “heat domes,” tend to bring a summer’s hottest weather. That’s because they deflect the jet stream to the north, which means any inclement weather, storm system and cloud bank gets shunted over the northern Intermountain West. Instead, sinking air brings sunny skies and dry conditions, which allow the region to heat up quickly.

The heat dome sprawled over the Southwest this weekend will shift toward the southeastern United States next week, where temperatures are projected to skyrocket.

The heat is being intensified by human-caused climate change. In Phoenix, the average June temperature has jumped from 83.7 degrees around World War II to 93.9 degrees now – a staggering spike. In Dallas, that same window has featured a jump from 80.8 to 83.4 degrees.

Some of that increase is because of the urban heat island effect, which is tied to development and paving surfaces with heat-absorbing materials, but substantial warming is also linked to increasing atmospheric concentrations of heat-trapping gases from fossil fuel burning.