Researchers found that some areas of South Africa, Mozambique and Zimbabwe received the equivalent of an entire year's rainfall in just 10 days — an extraordinary deluge that overwhelmed communities, destroyed infrastructure and caused widespread displacement.
Homes across Mozambique were left submerged, while key roads and bridges were washed away in South Africa's Limpopo and Mpumalanga provinces, as well as in parts of Zimbabwe. The destruction is expected to cost millions of dollars, alongside profound human losses.
The assessment, carried out by an international team of scientists, used peer-reviewed attribution techniques to examine how rising global temperatures are reshaping extreme weather events.
A rare event made far more severe
The researchers found that rainfall of this magnitude would historically be expected roughly once every half century. However, the data now point to a clear trend toward heavier and more violent downpours across the region.
While the current La Niña phase — which typically brings wetter conditions to southern Africa — played a role, scientists stressed that it unfolded in an atmosphere already warmed by human activity, dramatically increasing the storm's impact.
"Our findings show that continued fossil fuel use is not only strengthening extreme rainfall, but is also turning events that would have occurred anyway into something far more destructive," said Izidine Pinto, a senior climate researcher at the Royal Netherlands Meteorological Institute and co-author of the study.
Although models could not quantify the precise contribution of climate change to this specific disaster, Pinto noted that an estimated 40 per cent increase in rainfall intensity cannot be explained without human influence.
"What might once have been a serious weather event became a violent deluge that local communities simply weren't prepared for," he said.
Flooding exceeded all expectations
Southern Africa regularly experiences heavy rains, but experts say the scale of this episode caught even seasoned forecasters off guard.
"This was unexpected, even compared with floods we saw 25 years ago in the same areas," said Bernardino Nhantumbo of Mozambique's national weather service.
In some locations, rainfall recorded over just two or three days matched what is normally expected for an entire rainy season.
Mozambique's vulnerability was further compounded by its position downstream of nine international river systems, meaning intense rainfall upstream rapidly translated into surging river flows.
"Even with accurate forecasts, there are limits to how much damage can be prevented when events reach this scale," Nhantumbo said.
Central and southern Mozambique bore the brunt of the disaster, with large parts of Xai-Xai, the capital of Gaza province, and the nearby town of Chokwe left underwater.
Calls for Africa-led climate modelling
The scientists behind the study are also urging greater investment in climate research capacity across Africa, warning that the continent remains heavily reliant on models developed elsewhere.
Friederike Otto, professor of climate science at Imperial College London, said the absence of Africa-based climate models hampers precise assessments of how climate change is affecting the region.
"All freely available climate models are produced in the US, Europe or parts of Asia," she said. "There isn't a single model developed in Africa, and models tend to perform best in the regions they're designed for."
She added that building local modelling capacity would significantly improve understanding of regional risks and help governments better prepare for future extremes.