Most of the US population, 326 million people, have experienced at least one unusually hot summer day this summer, according to a new report by non-profit Climate Central.
The largest number of such days occurred in places in the US south, south-east and, most relentlessly, south-west.
“The trend is so strong there, every year just seems to be getting harder and harder in the south-west,” said Andrew Pershing, director of climate science at Climate Central, where he and his team measure the influence of climate change on daily temperatures. “But then we have other places in the country where the heat will pop up, and one of the lessons of the last few summers is that it can happen just about anywhere.”
A total of 175 of the 244 US cities analyzed had at least one week with extraordinarily warm temperatures made at least two times more likely by the climate crisis, with San Juan, Puerto Rico (90 days); Victoria, Texas (80 days); and Lafayette, Louisiana (74 days), topping the list. Ocean temperatures have also been at an all-time high, contributing to an intensifying hurricane season.
“Anywhere that’s surrounded by the ocean, because it is such a great storage medium for heat, a little bit of warming there comes out as highly significant in our analysis,” Pershing said.
A total of 45 US cities, most of which were in Texas and Florida, had at least half of all summer days with exceptionally warm temperatures made at least twice as likely due to the climate crisis.
“Almost everybody in the country had at least one day where the temperature was something that would be half as likely if we hadn’t put all this carbon dioxide in the atmosphere,” Pershing said.
Since 1 May, 96% of the US population has experienced at least one extreme weather alert, according to the Union of Concerned Scientists. It is more likely than not that the next summer will be even hotter.
“Heat is just part of our daily life now and everywhere needs to be prepared for this chronic stressor,” Pershing said.
A number of cities across Arizona, Louisiana, Texas, New Mexico and Alabama had streaks of days above 100F (37.7C). People in Phoenix, Arizona, experienced 56 consecutive days of 105F-plus (40.5C) temperatures, while San Antonio, Texas, and Lafayette, Louisiana, had 23 and 17 days in a row, respectively, of temperatures of at least 100F.
This summer was the hottest on record, surpassing the previous record set in the summer of 2019 by nearly a third of a degree celsius.
“The dog days of summer are not just barking, they are biting,” said the UN secretary general, António Guterres, in a statement last week in response to the record-breaking summer 2023 data reported by the European Union’s Copernicus Climate Change Service. “Climate breakdown has begun.”
