Brothers Fernando, left, and Jacob Ortega watch their dogs at White Rock Lake in Dallas, Tuesday, June 20, 2023. The brothers say they bring their dogs to the lake every day to cool off during summer. (AP Photo/LM Otero) 
A boxer puppy named Lexi, right, cools off in the water with other dogs at White Rock Lake in Dallas, Tuesday, June 20, 2023. It’s Texas, it’s summer, it’s hot. (AP Photo/LM Otero) 
A dog carries a tennis ball in the water at White Rock Lake in Dallas, Tuesday, June 20, 2023. It’s Texas, it’s summer, it’s hot. (AP Photo/LM Otero) 
Kristin Campbell fuels her car up at sunrise at the Murphy USA station at Walmart, Tuesday, June 20, 2023 in Owasso, Okla. Campbell drove to work early to make sure she could get gas. Heavy storms last weekend down trees and power lines. (Mike Simons/Tulsa World via AP) 
Dawn Borchert sleeps in her front yard in a neighborhood near 11th Street and Lewis Ave., Tuesday, June 20, 2023 in Tulsa, Okla. Borchert has been without power since the weekend storms and slept in a tent over night but moved outside to cool off in the morning. (Mike Simons/Tulsa World via AP) 
A man walks past downed power lines on Peoria Ave. and 14th Street Tuesday, June 20, 2023 in Tulsa, Okla. Heavy storms last weekend down trees and power lines. (Mike Simons/Tulsa World via AP) 
A utility crew works on downed utility lines near 21st Street and Boulder Ave. Tuesday, June 20, 2023 in Tulsa, Okla. Heavy storms last weekend down trees and power lines. (Mike Simons/Tulsa World via AP) 
Workers salvage personal belongings from their damaged vehicles outside of Merchants and Marine Bank in Moss Point, Miss., Tuesday, June 20, 2023, after a tornado damaged the building on Monday afternoon, trapping workers inside. (Hannah Ruhoff/The Sun Herald via AP) 
Standing in the mid afternoon heat, a worker takes a drink during a parking lot asphalt resurfacing job in Richardson, Texas, Tuesday, June 20, 2023. (AP Photo/LM Otero) 
Miguel, no last name given, shovels hot asphalt during a parking lot resurfacing job in Richardson, Texas, Tuesday, June 20, 2023. (AP Photo/LM Otero) 
Standing in the mid afternoon heat, a worker takes a break to drink during a parking lot asphalt resurfacing job in Richardson, Texas, Tuesday, June 20, 2023. (AP Photo/LM Otero) 
Electrical lines hang over the Broken Arrow Expressway after power poles were damaged during Saturday night’s storm on Tuesday, June 20, 2023, in Tulsa, Okla. In Oklahoma, more than 100,000 customers were eagerly awaiting the restoration of power and air conditioning following weekend storms that downed trees and snapped hundreds of utility poles. (Daniel Shular/Tulsa World via AP) 
Augustus Whitney, of Standby Personnel, stands near a collapsed section of the Liberty Towers parking garage wall that fell during Saturday night’s storm on Tuesday, June 20, 2023, in Tulsa, Okla. (Daniel Shular/Tulsa World via AP) 
Robert Fry with Up With Trees, center left, guides branches into a wood chipper on Boulder Avenue as Faustino Amador, center, moves more branches off the sidewalk from Saturday night’s storm on Tuesday, June 20, 2023, in Tulsa, Okla. (Daniel Shular/Tulsa World via AP) 
A fallen tree from during Saturday night’s storm lays across Quincy Avenue near 13th Street over a parked car on Tuesday, June 20, 2023, in Tulsa, Okla. (Daniel Shular/Tulsa World via AP)
AUSTIN, Texas | Texas’ power grid operator asked residents Tuesday to voluntarily cut back on electricity due to anticipated record demand on the system as a heat wave kept large swaths of the state and southern U.S. in triple-digit temperatures.
On the last day of spring, the sweltering heat felt more like the middle of summer across the South, where patience was growing thin over outages that have persisted since weekend storms and tornadoes caused widespread damage.
In the Mississippi capital, some residents said Tuesday that they had been without power and air conditioning for almost 100 hours, which is longer than the outages caused by Hurricane Katrina in 2005. Entergy Mississippi, the state’s largest electric utility, said its crews had worked 16-hour shifts since Friday, but some officials expressed doubts about its preparedness.
High temperatures in the state were expected to reach 90 degrees (32 degrees Celsius) on Tuesday.
“The delay in restoring power has caused significant hardship for their customers and it is unacceptable,” said Brent Bailey, a member on the Mississippi Public Service Commission, the state’s energy regulator.
The request by the Electric Reliability Council of Texas, which serves most of that state’s nearly 30 million residents, was its first of the year to cut energy consumption. ERCOT said it was “not experiencing emergency conditions,” but it noted that the state set an unofficial June record on Monday for energy demand.
In the oil patch of West Texas, temperatures in San Angelo soared to an all-time high of 114 degrees (46 degrees Celsius) on Tuesday, according to the National Weather Service.
Many Texans have been skeptical of the state’s grid since a deadly 2021 ice storm knocked out power to millions of customers for days. Republican Gov. Greg Abbott has said improvements since then have made the grid more stable, but those improvement efforts continue to draw scrutiny.
In neighboring Oklahoma, more than 100,000 customers were eagerly awaiting the restoration of power and air conditioning following weekend storms that downed trees and snapped hundreds of utility poles. Officials say at least one person in Oklahoma has died because of the prolonged outages, which could last into the weekend for some residents.
Arkansas Gov. Sarah Huckabee Sanders on Tuesday declared a state of emergency because of the weekend’s storms, citing damage from the weather and “numerous” downed power lines.
In Louisiana, more than 51,000 electricity customers were still without power Tuesday because of the storms that damaged more than 800 structures around Shreveport alone, according to Mayor Tom Arceneaux. Officials said more than a dozen major transmission lines were still awaiting repairs.
Associated Press writers Michael Goldberg in Jackson, Mississippi, and Andrew DeMillo in Little Rock, Arkansas, contributed to this report.