More than 100 million people, around a third of Americans, were under extreme heat advisories this weekend and that record-breaking heat was expected to continue into the new week.
There were advisories from coast to coast, with the south-west and parts of the west hard hit and officials warning that conditions could get worse in Arizona, California and Nevada.
Residents were warned to “take the heat seriously and avoid time outdoors” by the National Weather Service, which said it was “potentially deadly to anyone without effective cooling and/or adequate hydration”.
Cooling centers extended their hours in some cities and emergency rooms prepared to treat more people with heat-related illnesses.
In Phoenix, Arizona, the forecast for Sunday was for 118F (47.7C) and it was expected to be the city’s 17th consecutive day of 110F (43.3C) or higher. The record was 18 days, in 1974, which the city seems likely to pass on Tuesday.
According to the Maricopa county health department, there have been 12 heat-related deaths in the Phoenix area so far in 2023, with 55 other deaths currently under investigation.
“Record heat continues across the region today and through most of this upcoming week,” said National Weather Service Phoenix on Sunday. It shared safety tips such as drinking plenty of water and checking on relatives and neighbors.
Ahead of the weekend, David Hondula, chief heat officer for Phoenix had warned: “This weekend there will be some of the most serious and hot conditions we’ve ever seen.”
Hondula said just one location, the Brian Garcia Welcome Center for homeless people in downtown Phoenix, planned to be open 24 hours and directed people to shelters and other air-conditioned spaces for the night. During especially hot spells in the past, the Phoenix convention center has opened some space as a night-time cooling center, but Hondula said he had not heard of that possibility this year.
Stacy Champion, an advocate for homeless people in Phoenix, took to Twitter this week to criticize the lack of night-time cooling spaces for unsheltered individuals, saying they are “out of luck” if they have no place to go.
Emphasizing how dangerous the heat can be, police in the Phoenix suburb of Surprise said on Saturday that its officers on Friday found two older women sweltering at home in 114F (45.5C) temperatures with just a tiny, overtaxed air-conditioning unit that failed to cool most of the house.
After the women were taken to senior center to cool off, the department’s community services team bought and installed an adequate air conditioner and several fans in the home.
In Las Vegas, casinos offered respite from the heat for many. Air-conditioned libraries, police station lobbies and other places from Texas to California planned to be open to the public to offer relief for at least part of the day.
Emergency room doctors in Las Vegas have been treating more people for heat illness as the heatwave threatened to break the city’s all-time record high of 117F (47.2C) this weekend.
Dr Ashkan Morim, who works in the ER at Dignity Health Siena hospital in suburban Henderson, Nevada, spoke on Friday of treating tourists this week who spent too long drinking by pools and became severely dehydrated, and a stranded hiker who needed liters of fluids to regain his strength.
In New Mexico’s largest city of Albuquerque, splash pads will be open for extended hours and many public pools were offering free admission. In Boise, Idaho, churches and other non-profit groups were offering water, sunscreen and shelter.
In southern California, temperatures soared into the triple digits in inland areas, and a ridge of high pressure was expected to keep its hold on the region for a couple of weeks.
By mid-Saturday afternoon, it was 122F (50C) in Death Valley, California, where forecasters have said the temperature could hit 130F (54.4C) this weekend. The hottest temperature recorded at Death Valley was 134F (56.6C) in July 1913, according to the National Park Service.
In Los Angeles, Mayor Karen Bass announced the city was opening cooling centers where residents can escape the heat. “The extreme heat that is forecasted this weekend can pose serious risks,” she warned.
The hot, dry conditions sparked a series of blazes in southern California south-east of Los Angeles, where firefighters on Saturday were battling three separate brush fires amid blistering heat and low humidity in sparsely populated, hilly areas. The fires were all within 40 miles (65km) of each other in Riverside county, where temperatures in some areas spiked into the triple digits.
Some cities were taking steps to protect outside workers.
On Tuesday, 18 July, the Miami Dade board of commissioners is scheduled to consider a heat standard ordinance for the county that would mandate water breaks, shade and rest for outdoor workers. Miami is under an excessive heat warning until 7pm tomorrow, with feel-like temperatures expected today of up to 112F and 108F on 17 July.
In Maryland, the state reported the first heat-related death of 2023 on 13 July, a 52-year-old man in Cecil county, as temperatures in the state hit the mid- to upper 90s.
On the Sunday politics TV shows, lawmakers and officials faced questions over the heatwave and the climate crisis.
On CNN’s State of the Union, Senator Mark Kelly of Arizona was asked about suggestions from other lawmakers that Fema should provide financial assistance to states suffering extreme heatwaves in a similar way to hurricanes, tornadoes or floods.
Kelly said: “I think maybe in some cases … that could be an approach here.”
“We’ve got to continue to work towards reducing the amount of carbon dioxide we’re putting in the atmosphere,” the senator added and described steps being taken to speed the transition to clean energy helped by the Inflation Reduction Act climate legislation that was passed last August.
The national security adviser, Jake Sullivan, was asked on CNN about the global response to the climate crisis, and if it was time for the UN to stop allowing China to be categorized as a developing nation when it comes to emissions cuts.
Sullivan said that the US climate envoy, John Kerry, would make the point during his trip to Beijing that started on Sunday that there was “more work for them to do on that front” and that “every country including China has a responsibility to reduce emissions” and China should be encouraged to “take far more dramatic action”.
As parts of the US faced extreme heat, the north-east of the US was hit by flooding, with officials saying on Sunday that a flash flood on a road in Pennsylvania had killed three people with four others, including a baby, missing, AP News reported.