- A rapid analysis of heavy floods that occurred between December 2025 and January 2026 in Southern Africa finds that climate change has exacerbated extreme rainfall events.
- Scientists found that rainfall events in the region seem to be becoming more intense, and the likelihood of extreme precipitation occurring is higher in a warmer world.
- Despite limitations of climate models in the African context, scientists say they’re confident that weather patterns are shifting due to climate change.
- The study also revealed that the impacts were heightened due to structural and social vulnerabilities in the affected countries, with Mozambique being the hardest hit.
Devastating floods that swept across Southern Africa since December 2025, killing at least 280 people and affecting almost a million, were likely intensified by the impacts of climate change, scientists say.
The region’s rainy season hit hard in Mozambique, Eswatini, Madagascar, South Africa and Zimbabwe, displacing 150,000 people and destroying 105,000 hectares (nearly 260,000 acres) of farmland. Most recently, Cyclone Gezani hit Madagascar on Feb. 10, leaving dozens dead. The storm also caused deaths and damages in flood-battered Mozambique.
A rapid study by World Weather Attribution (WWA), an international consortium of scientists and institutions that investigates the role of human-caused climate change in extreme weather events, found that a warming climate, combined with La Niña weather patterns, aggravated the extreme rains.
“The most striking finding was that the rainfall accumulated over just 10 days exceeded the region’s average annual rainfall. This was unprecedented,” one of the study’s lead authors, Izidine Pinto, climatologist and researcher for weather and climate models at the Royal Netherlands Meteorological Institute, told Mongabay. He added that some weather stations recorded more than 200 millimeters (8 inches) of rain in just 24 hours.
The authors noted that structural vulnerabilities in the affected areas made the climatic shocks even deadlier and more destructive. Mozambique, in particular, Pinto said, was not prepared for such heavy rainfall.
The WWA scientists analyzed 10-day maximum rainfall accumulations during the rainy season in Mozambique, South Africa, Eswatini (formerly known as Swaziland) and Zimbabwe from December to the beginning of February. By combining this data with climate models, the authors found that these countries are witnessing more frequent bouts of consecutive rainy days, and that rainfall events are becoming more intense.
The current rainy season has been influenced by La Niña events, an unusual cooling of the waters of the tropical Pacific Ocean that rolls around every three to five years and influences weather patterns worldwide. In Southern Africa, La Niña is linked with heavy precipitation. Under La Niña conditions, the likelihood of an extreme 10-day rainfall event increases fivefold. Rainfall intensity also increases by about 20%.
With a change in underlying climatic conditions, that increase in intensity is now at 40%.
“Natural climate variability such as La Niña still influences wet years, but climate change is making the wet years significantly wetter and more damaging than they would have been decades ago,” Pinto said.
The WWA study found that impacts from these climatic disasters are amplified because of the disproportionate effects on poor and marginalized communities. “Poor housing quality and inadequate infrastructure significantly increased exposure and vulnerability to flooding,” the authors said.
The floods damaged health facilities, destroyed medicine stocks, and cut off people’s access to health care centers, disrupting life-sustaining care.
What’s eroding people’s ability to respond and recover is that they face not just one extreme weather event in isolation, but a series of them, according to experts like Richard Munang, the Africa Regional Climate Change Coordinator at the United Nations Environment Programme (UNEP).
“Here is what rarely enters this conversation: these same communities were still recovering from the severe 2023/2024 drought,” Munang, who is also UNEP’s head of global environment monitoring systems, told Mongabay by email. “Crops had failed, savings were depleted, and health services were already stretched. Before they could stand up from the drought, the flood knocked them down again.”
Munang added that these are not two separate disasters, but part of the same cycle: “Drought, followed by flood, followed by a disease outbreak.”
The WWA study revealed that communities affected by the rains have limited capacity to cope with the floods, which can increase the risk of disease outbreaks.
Mozambique was the hardest hit by the heavy rains over the last few months, as it lies downstream of nine transboundary rivers. “When heavy rains fell in South Africa and Zimbabwe, controlled dam releases sent additional water toward communities [in Mozambique] already inundated,” Munang said. On top of this, 90% of Mozambicans live in adobe houses — traditional structures built from sun-dried bricks of earth, water and straw — which are prone to damage from sustained heavy rain.
“For southern Mozambique, the transition from drought to floods is more than just bad weather; it is a compound crisis that multiplies human suffering,” Pinto said.
For example, relief agencies warn that the impacts of the heavy rains could exacerbate an ongoing cholera outbreak in large parts of Mozambique. The risk of cholera, a waterborne disease, grows when people have reduced access to clean drinking water and sanitation facilities.
To adapt to future climate conditions, governments rely on climate modeling to inform infrastructure and planning decisions. The WWA study may have established that, with a warming planet, events like those seen over the past few months are more likely to occur in the region; however, the climate models used didn’t account for the compounding impacts from La Niña.
“Every freely available model originates from the US, Europe, or Asia, optimized for those regions’ weather patterns,” Munang said, which means that the early warning systems, infrastructure planning decisions, and dam release protocols across Africa currently rely on models that are less accurate for African conditions.
For Munang, this means there’s an inherent bias in these tools, as they may miss key phenomena such as the interaction between temperature conditions in the Indian and Pacific oceans, which drive Southern Africa’s rainfall, or how floodwaters from rains in South Africa and Zimbabwe end up in rivers flowing through Mozambique.
Since the flooding happened during a high tide event along the coast, it prevented floodwater from the rivers from draining out to sea, Munang said. “Global models do not capture these local dynamics.”
The WWA study acknowledges modeling limitations, as the approximations the models used to validate observations don’t originate from this region. “The confidence in linking the intensity of the January 2026 event to climate change is limited by shortcomings of climate models considered,” Stefaan Conradie from the Climate System Analysis Group at the University of Cape Town, South Africa, which contributed to the WWA study, told Mongabay by email. None of the models that researchers applied was “able to satisfactorily reproduce the observed correlations with … the role of La Niña conditions in enhancing rainfall,” the authors wrote.
Conradie added that despite this, there’s enough evidence to link the intensity of extreme rainfall events over the eastern flank of Southern Africa with the “warming oceans and the capacity of warmer air to hold more moisture.”
Given the shift occurring in climatic conditions across sub-Saharan Africa, and in particular Southern Africa, the question will be how governments respond and shape their adaptation strategies, Munang said: “[The ones that] treat floods as isolated events will continue to fail because they miss this compound reality.”
Banner image: Mozambique was the hardest hit by the heavy rains in the last few months, since it’s located downstream of nine international rivers. Image © European Union, 2025 (Peter Biro) via Flickr (CC BY-NC-ND 4.0).
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