Rain is expected to bring respite to heat-weary residents of Phoenix, Arizona, as the city in the southwestern United States struggles with a record 31 consecutive days of temperatures hitting at least 43.3 degrees Celsius (110 degrees Fahrenheit).
Seasonal thunderstorms could drop temperatures on Monday and Tuesday, forecasters said.
“It should be around 108 degrees [Fahrenheit, 42.2C], so we break that 110 streak,” meteorologist Tom Frieders said. “Increasing cloud cover will put temperatures in a downward trend.”
The relief could be short lived, however, as temperatures are expected to creep back to 43.3C (110F) on Wednesday and climb even higher to reach 46.1C (115F) by the end of the week.
Globally, July will likely be the hottest month on record and possibly the warmest in 120,000 years, climate scientists said, as several countries saw record temperatures.
In the US last week, President Joe Biden announced new support for workers and communities hit by the heatwave, which he said was affecting more than 100 million Americans.
“I don’t think anyone can ignore the impact of climate change any more,” Biden said during a news conference, pointing to historic flooding, droughts, hurricanes and increasingly devastating wildfires across the country.
The historic heat began blasting the lower southwest in late June. Its effects have stretched from Texas across New Mexico and Arizona and into California’s desert.
On Sunday, a wildfire burning out of control in California’s Mojave National Preserve spread rapidly amid erratic winds. The blaze, called the York Fire, erupted on Friday near the remote Caruthers Canyon area. It has since sent up a huge plume of smoke visible nearly 160km (100 miles) away across the state line in Nevada.
Flames 6 metres (20 feet) high in some spots have charred more than 284sq km (110sq miles) of desert scrub, juniper and Joshua tree woodland, according to a Sunday update.
“The dry fuel acts as a ready ignition source, and when paired with those weather conditions, it resulted in long-distance fire run and high flames, leading to extreme fire behavior,” authorities said.
Meanwhile, firefighters reported progress against another major blaze to the south, in Riverside County, that prompted evacuations. The Bonny Fire was about 10 percent contained as of Sunday, as firefighters worked on building a containment perimeter around the burning area.
Back in Phoenix, doctors have treated numerous patients who suffered burns from falling on scalding pavement or touching surfaces that were much hotter than the recorded air temperature.
Asphalt and concrete in direct sunlight can often reach surface temperatures as high as 82C (180F) on the hottest days, said Dr Kevin Foster, who directs the Arizona Burn Center in Phoenix.
The health department in Maricopa County, which includes Phoenix, has reported at least 25 heat-related deaths so far this year, according to its most recent heat report, ending on July 22. Another 249 deaths were under investigation, it said.
Meanwhile, poorer Americans and people of colour are far more likely to face gruelling heat without air conditioning, according to a Boston University analysis of 115 US metro areas.
The record heat has prompted calls for more support for at-risk communities trying to stay cool and for governments to take action to tackle the climate crisis.
Experts say climate change is making severe heatwaves more common around the world.
