Summer 2024 was the hottest on record, according to the European Union's climate change monitoring service.
A season of heatwaves, intensified by human-driven climate change, saw June to August surpass the previous record set last year, with an average temperature of 16.8°C, the Copernicus Climate Change Service (C3S) said in its monthly bulletin.
The exceptional heat increases the likelihood that 2024 will outrank last year as the planet's warmest on record, it said.
"During the past three months of 2024, the globe has experienced the hottest June and August, the hottest day on record, and the hottest boreal summer on record," said C3S deputy director Samantha Burgess.
From June to August, the global temperature was more than 1.5°C warmer than the pre-industrial average – a key threshold for limiting the worst effects of climate change.
Copernicus records date back to 1940, but American, British and Japanese records, which start in the mid-19th century, show the past decade has been the hottest since regular measurements were taken and likely in about 120,000 years, according to some scientists.
“What those sober numbers indicate is how the climate crisis is tightening its grip on us,” said Stefan Rahmstorf, a climate scientist at the Potsdam Institute for Climate Research in Germany, who wasn't part of the research.
Heat was exacerbated in 2023 and early 2024 by the cyclical weather phenomenon El Nino, although Copernicus scientist Julien Nicolas said its effects were not as strong as they sometimes are.
Meanwhile, the contrary cyclical cooling phenomenon, known as La Nina, has not yet started, he said.
Greenhouse gas emissions from burning fossil fuels are the main cause of climate change.
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The planet's changed climate continued to fuel disasters this summer.
In Sudan, flooding from heavy rains last month affected more than 300,000 people and brought cholera to the war-torn country.
Elsewhere, scientists confirmed climate change is driving a severe drought on the Italian islands of Sicily and Sardinia, and it intensified Typhoon Gaemi, which tore through the Philippines, Taiwan and China in July, leaving more than 100 people dead.
Unless countries urgently reduce their planet-heating emissions, extreme weather "will only become more intense", said Ms Burgess.
Human-caused climate change and the El Nino natural weather phenomenon, which warms the surface waters in the eastern Pacific Ocean, pushed temperatures to record highs earlier in the year.
Copernicus said below-average temperatures in the equatorial Pacific last month indicated a shift to La Nina, which is El Nino's cooler counterpart.
But that didn't prevent unusually high global sea surface temperatures, with average temperatures in August hotter than in the same month of any other year, except for 2023.
Governments have targets to reduce their countries' planet-heating emissions to try to keep the rise below 1.5°C under the 2015 Paris Agreement.
The average level of warming is currently about 1.2°C, according to the World Meteorological Organisation.
Copernicus said the 1.5°C level has been passed in 13 of the past 14 months.
