Last month was the second-warmest September ever registered globally in an exceptional year "almost certain" to become the hottest on record, the EU climate monitor Copernicus said on Tuesday.
The Copernicus Climate Change Service (C3S) said the average global temperature last month was second only to September 2023.
September saw "extreme" rainfall and destructive storms in many parts of the world, events that are occurring with greater severity and frequency as global temperatures rise due to climate change.
Warmer air can hold more water vapour, and warmer oceans mean greater evaporation, resulting in more intense rainfall.
Hurricane Helene pounded the southeast United States, Typhoon Krathon slammed into Taiwan and Storm Boris brought floods and devastation to central Europe in a month of wild weather.
"The extreme rainfall events of this month, something we are observing more and more often, have been made worse by a warmer atmosphere, leading to more intense rainfall with months' worth of rain falling in just a few days," said Samantha Burgess, Deputy Director of the Copernicus Climate Change Service (C3S).
2023 was the warmest year ever recorded but the months January through to September 2024 have set fresh highs, said Copernicus.
The monitor said it was "almost certain that 2024 is going to be the warmest year on record".
Copernicus records go back to 1940 but other sources of climate data such as ice cores, tree rings and coral skeletons allow scientists to expand their conclusions using evidence from much further in the past.
