By Erin Douglas
The Texas Tribune
An unrelenting stretch of blistering days amid an ongoing heat wave has put this summer on track to be one of Texas’ most extreme, weather data shows.
Although June was only Texas’ 16th warmest on record by average temperature, according to the state climatologist, a long period of very hot days between mid-June and mid-July has made this summer one of the most intense in terms of extended high temperatures.
In June, a sample of 38 weather stations across the state recorded a temperature at or above 100 degrees 250 times — the fifth-greatest monthly total for that month in the past three decades, according to a Texas Tribune analysis of National Weather Service data. The average temperature for June was 82.2 degrees, which was 2.6 degrees above the 20th century average, according to data provided by the state climatologist.
Heat waves — and the record-breaking temperatures they bring — are becoming more common and severe due to climate change, scientists have found. In the past decade in Texas, there were 1,000 more days of record-breaking heat than in a normal decade, a Tribune analysis found.
“As we warm the atmosphere, the likelihood that we will have days over 100 degrees is higher,” said Sylvia Dee, a Rice University climate scientist. “The tails, or extremes, will be hotter.”
Still, this summer has yet to exceed last summer’s historic heat. Last year was Texas’ second-hottest summer on record, by average temperature. Climate change, combined with a severe drought and La Niña weather pattern made for hot days and nights. Much of the state got enough rain earlier this year that reduced or eliminated drought conditions across the state and provided some cooling.
“We could conceivably crack the top three [warmest summers] but would have a hard time beating the summer averages from last year,” said John Nielsen-Gammon, the state climatologist.
This year, an El Niño pattern has developed, meaning higher-than-average surface sea temperatures. In Texas, an El Niño pattern usually brings more moisture and a cooling effect with it. However, the length and duration of the heat wave this year has dominated the weather pattern instead.
The high-pressure weather system bearing down on the Southwest has made West Texas and the Rio Grande Valley particularly intolerable this summer.
In El Paso, it’s been more than a month since temperatures didn’t reach 100 degrees — the longest stretch of 100-degree heat ever in that area.
The previous record was set in 1994 with a 23-day long stretch of 100-degree heat, said Jason Grzywacz, a meteorologist for the National Weather Service in El Paso.
Though El Paso has not set very many all-time temperature records this year, it’s the relentlessness of the extreme heat that’s particularly notable this summer, Grzywacz said. Typically in El Paso, a monsoon pattern develops in early July that brings moisture, breaking up a heat wave, he said. But this year, the strength of the high-pressure system is pushing out any chance of rainy weather that could cool the area.
“We usually don’t get this string [of high-heat days] into mid-July,” he said. “But the high [pressure system] has just been sitting on the four corners [of Colorado, New Mexico, Arizona and Utah], so the moisture isn’t being brought in like it normally would.”
There’s little relief in sight for West Texas: Nighttime temperatures have stayed in the 80s this summer, he said. Usually, El Paso’s summer nights dip down to at least the 70s.
“We’re running a good 6 to 12 degrees above normal [this summer], as far as low temperatures go,” Grzywacz said.
As climate change pushes temperatures up over time, average nighttime temperatures globally are warming faster than daytime temperatures, scientists have found.
In McAllen, the annual heat wave that smothers northern Mexico and its border with Texas — locals call it “La Canícula” — came earlier this year, said Barry Goldsmith, warning coordination meteorologist at the National Weather Service in Brownsville.
Since June 12, McAllen has recorded 30 days at or above 100 degrees, the second-longest such stretch since 1941, when recording began at that weather station. McAllen should soon break the all-time record of 31 triple-digit days, set in 1988.
“We’ve had full months of July be 100 [degrees] plus in McAllen,” Goldsmith said. “But what makes this year different is June.”
Goldsmith said the early and sudden onset of the heat wave is likely contributing to the spiking rates of emergency room visits in South Texas.
“Heat is a normal thing down here — don’t get me wrong, we are used to heat,” Goldsmith said. “But we had a sharp shift in the pattern. … We just flipped the switch.”
If the heat wave continues, McAllen and other parts of Texas could break all-time records.
“We are pretty convinced July in McAllen will [continue topping] 100 degrees,” Goldsmith said. “The question becomes August.”
This article originally appeared in The Texas Tribune at https://www.texastribune.org/2023/07/18/texas-heat-summer-extreme-weather/.