The southwestern United States, from California to Arizona, is expected to see prolonged record temperatures this week, with temperatures in some places rising to near 120°F.
The most dangerous temperatures are expected Monday through Wednesday, though extreme heat could linger into Thursday. Temperatures are expected to peak on Tuesday: Death Valley, California, could record temperatures as high as 127°F, and the Colorado River Valley could see temperatures as high as 122°F.
The record-high temperatures are a sign that monsoon season is right around the corner, according to the Washington Post. The southwest often sees the highest temperatures of the year right before the wettest months, as warm temperatures create an area of low pressure that, in turn, draws moisture to the region.
In Phoenix, temperatures are expected to climb above the range in which some commercial airplanes can safely fly (small commercial planes are only able to operate in temperatures up to 118 degrees Fahrenheit). American Airlines has already cancelled 38 flights out of Phoenix, and it’s possible that more flights could be grounded as temperatures are expected to peak on Tuesday.
Across the United States, unusually hot days, along with unusually hot nighttime temperatures, have become increasingly common in recent years. When nighttime temperatures remain high, the body cannot cool off as easily as when nighttime temperatures are low — making heat waves even more dangerous as the human body strains to regulate temperature.
The southwest is already one of the hottest parts of the United States, which means that it regularly sees some of the country’s highest temperatures before monsoon season arrives. But as Arizona-based meteorologist Eric Holthaus noted on Twitter, Arizona has seen a marked jump in the average number of days above 100 degrees Fahrenheit in recent years — in Tucson for instance, the number of extremely hot days has increased 55 percent in the last 30 years.
Before the temperatures break, however, the region will have to contend with record-breaking temperatures, and the increased potential for wildfires as a result. Firefighters in California battled a brush fire in Los Angeles County over the weekend, which had burned 800 acres and was 60 percent contained as of Monday.
Extreme heat is one of the clearest and more defining characteristics of global warming, according to more than 20 different scientific studies that looked at the connection between climate change and extreme heat events. A new study conducted by researchers at the University of Hawaii found that nearly a third of the world’s population is currently exposed to dangerous heatwaves for 20 or more days per year because of global warming. And, the researchers warn, that number could climb even higher — to almost half of the world’s population by 2100 — if carbon emissions are not dramatically reduced.
“Dying in a heatwave is like being slowly cooked, it’s pure torture,” Camilo Mora, lead author of the study, told the Guardian. “The young and elderly are at particular risk, but we found that this heat can kill soldiers, athletes, everyone.”
Heat waves have been responsible for tens of thousands of deaths in recent years. In 2003, a heatwave killed an estimated 20,000 in Europe, though a subsequent study estimates that as many as 70,000 could have died. In 2010, 10,000 died during a heatwave in Moscow, with temperatures climbing above 100°F in the Russian capital. And in 2015, a heat wave in India — which saw temperatures rise to 113.7°F — killed more than 2,300 people.
President Donald Trump, for his part, does not accept the scientific consensus on human-driven climate change. He has, on multiple occasions, used unusually cold weather as evidence that global warming is “a hoax.” When the East Coast was hit with record-breaking warm temperatures in February, however, Trump did not comment on the weather.
As president, Trump has systematically set about rolling back environmental and climate regulations, including repealing the Clean Power Plan and withdrawing the United States from the Paris climate agreement. These efforts — in conjunction with his administration’s goal to extract and burn more fossil fuels for energy — will likely increase the amount of carbon dioxide the United States emits, ultimately fueling the kind of deadly heat waves that have become increasingly common in recent years.