Europe isn’t the only place baking in extreme heat right now: an expanding heat dome over the central United States has smothered much of the country in soaring temperatures, and people have already begun to die from exposure.
The US National Weather Service (NWS) issued excessive heat warnings and heat advisories across 28 US states on Wednesday, mostly concentrated in the southern Great Plains but stretching across the country, from New Hampshire to California. The warnings cover some 100 million Americans, and millions more will begin to experience similar heat in the coming days.
In Oklahoma on Tuesday, every single weather-observing location in the state recorded a temperature of at least 102 degrees Fahrenheit, with many showing above 110 degrees in the midday heat, and many states in the region have shattered their record highs in recent days.
The NWS has described the heat wave as “dangerous,” noting that elderly people and those with heart-related illnesses are at particular risk.
The extreme heat is being caused by a “heat dome,” which the National Ocean Service defines as “when the atmosphere traps hot ocean air like a lid or cap.”
Essentially, the jet stream pulls warm, moist air from over the ocean down across the land, which warms and dries out as it descends, creating a semi-stable area of high pressure that blocks cloud formation and creates extremely hot temperatures at the surface that can persist for weeks.
During one of the worst heat waves of the last century, in 1936, triple-digit temperatures reached as far north as Canada, and it was possible to cook a steak rare in the street in North Dakota (that’s about 125 degrees Fahrenheit for readers not culinarily inclined). Ironically, this followed one of the coldest winters on record, when many died from hypothermia and large bodies of water like the Chesapeake Bay completely froze over.
In Arizona’s Maricopa County, which includes the capital city of Phoenix, at least 17 people have died from heat-related causes in 2022, with another 126 under investigation, according to the county health department. In a Phoenix suburb last week, a delivery driver shared home security video of a delivery driver who briefly collapsed on his porch due to the extreme heat, which reached 110 Fahrenheit that day.
The heat wave comes as parts of Europe are suffering even more extreme heat. In parts of a continent so unsuited to hot weather that few even have air conditioners, temperatures have soared to record highs. In Spain and Portugal, nearly 2,000 people have already died due to the heat, and the UK’s London documented a record high of 104 degrees Fahrenheit on Tuesday.
Separately in Japan, more than 20,000 people were hospitalized in the first week of July for heat stroke.
Meanwhile, more equatorial parts of the world have been suffering from even worse heat. In northwestern India and eastern Pakistan this year, one heat wave has followed another, with temperatures in New Delhi reaching 120 degrees Fahrenheit in early May. A 2019 report by researchers at the University of Chicago warned that by 2100, extreme heat could kill 1.5 million Indians every year.