As floodwaters coursed through Texas and Taiwan, as mosquito-borne viruses spread across the Americas, as lethal heat struck down children on hikes and grandparents on pilgrimage, the world’s average temperature this summer soared to the highest level in recorded history, according to new data from Europe’s top climate agency.

Global temperatures between June and August were 1.5 degrees Celsius (2.7 degrees Fahrenheit) above the preindustrial average, the Copernicus Climate Change Service said Friday — just edging out the record set last summer. The sweltering season reached its apex in late July, when Copernicus’s sophisticated temperature analysis program detected the four hottest days ever recorded.

Meanwhile, temperatures for the year to date have far exceeded anything seen in the agency’s more than 80 years of recordkeeping, making it all but certain that 2024 will be the hottest year known to science.

To Copernicus director Carlo Buontempo, the onslaught of broken records is sobering but not surprising. Humanity continues to burn fossil fuels at an ever-increasing pace, and the concentration of carbon dioxide in the atmosphere is higher than the world has seen in roughly 3 million years, according to the U.N. Intergovernmental Panel on Climate Change.

“If you keep doing the same thing, you cannot expect to get any different result,” Buontempo said. “Unless we limit greenhouse gases, we will only see an exacerbation of these temperatures.”

This summer came on the heels of an unprecedented year-long stretch in which Earth’s temperature repeatedly met or exceeded 1.5 degrees Celsius above the preindustrial average — a threshold scientists say the world cannot surpass if it hopes to avoid the worst consequences of climate change. The scorching conditions were the product of a complex cocktail of human-caused climate change and a strong El Niño event — a natural phenomenon characterized by warm temperatures in the Pacific Ocean.

Though the El Niño was declared over in June, huge amounts of energy remained trapped in the Earth’s system, Buontempo said, fueling the summer’s extraordinary temperatures.

The consequences were felt by people on every continent, from world-class athletes competing in the Paris Olympics to refugees fleeing wars. Wildfires fueled by heat and drought raged through the Brazilian Pantanal, a vital wetland known to store vast amounts of carbon. A turbocharged monsoon triggered landslides that killed hundreds of people in India’s Kerala state. The Atlantic Ocean saw its earliest Category 5 hurricane on record, while deadly floods have wreaked havoc from Italy to Pakistan to Nigeria to China.

It was a summer of unrelenting humidity and heat too extreme for the human body to withstand. In June, at least 1,300 pilgrims visiting the Muslim holy city of Mecca died amid temperatures of 50 degrees Celsius (122 degrees Fahrenheit). In Mexico, 125 people were reported dead during a July streak of exceedingly hot nights that researchers say was made 200 times as likely by climate change. And in the Arctic archipelago of Svalbard, one of the world’s northernmost inhabited areas, August temperatures soared more than 2.5 degrees Celsius (4.5 degrees Fahrenheit) above the record.

Nearly 7,000 weather stations in the United States broke daily temperature records between June 1 and Aug. 31, according to the National Oceanic and Atmospheric Administration. The heat has been blamed for dozens of fatalities, including those of a motorcyclist riding in Death Valley, an infant on a boat trip in Arizona and a California man who collapsed inside his un-air-conditioned home. In Maricopa County, Ariz. — one of the few jurisdictions to methodically track and report on the problem — officials have attributed at least 177 deaths this year to heat-related causes.

Some of the most unusual heat this summer occurred in Antarctica, where plumes of warm air disrupted the deep freeze of the six-month polar night. Temperatures on the continent spiked about 28 degrees Celsius (50 degrees Fahrenheit) above usual levels, and the surrounding sea ice shrank to nearly unprecedented lows.

The changes in Antarctica are especially eye-opening, Buontempo said, because the region has historically been isolated from the rest of the warming planet by a strong polar vortex and the swirling Southern Ocean.

But since 2023, the extent of sea ice around Antarctica has been about 1 million to 2 million square kilometers less than in any year since satellite observations began.

“This is very different from what we have seen in the past,” Buontempo said. “Even people working on sea ice are puzzled by the extent and the rapidity of the decline.”

When Earth’s four hottest days were recorded in July, climate scientist Johan Rockström told The Washington Post that the planet was probably the warmest it has been since the last ice age began more than 100,000 years ago. Climate clues contained in ice cores, lake sediments and tree rings show that global temperatures are shifting out of the range they’ve occupied for most of human history.

“We’re scratching 1.5 [degrees above preindustrial], and we’ve experienced how it hurts the economy, people and societies across the entire world,” said Rockström, director of the Potsdam Institute for Climate Impact Research.

“But within five to 10 years … what we’re experiencing right now will be looked back upon as a mild year,” he added. “We are inevitably in for a rough ride.”