In February 2025, a relentless five-day downpour drenched the South African region, a recurring event that once again exposed the area’s lack of readiness for such extreme weather.
The mid-February 2025 rainfall triggered disastrous floods in southern Botswana and eastern South Africa, displacing approximately 5,000 people.
These floods claimed at least 31 lives, including 22 in KwaZulu-Natal (Mhlophe-Gumede, 2025), near Durban, and at least nine in Botswana’s capital, Gaborone, among them six children (Government of Botswana, 2025).
From February 16th to 20th, the torrential rains ravaged the Botswana-South Africa border region, crippling both nations. Major entry ports into South Africa shut down, Botswana’s government schools closed temporarily, and traffic snarled into widespread chaos. Many communities found themselves isolated, with residents marooned and emergency crews racing to manage the fallout. Many areas became completely cut off, leaving residents stranded and emergency services scrambling to respond to the aftermath.
A team of 15 researchers from the World Weather Attribution group spanning experts from universities and meteorological agencies in Botswana, Denmark, Mexico, the Netherlands, South Africa, Sweden, the UK, and the US investigated the disaster and compiled a study. Leveraging satellite imagery, weather data, and climate models, they assessed how climate change fueled the five-day rainfall that triggered the floods.
The study found that the impact of heavy rainfall was exacerbated by inadequate infrastructure, rapid urbanization, and insufficient drainage capacity. This presents a critical challenge for Africa, the fastest urbanizing continent, where cities like Gaborone are expanding rapidly without corresponding infrastructure development, leaving essential systems highly vulnerable.
Analyzing the five-day heavy rainfall event in February 2025, scientists determined that it was a rare occurrence unlikely in a much colder climate. Weather station data from Gaborone indicates that such an event has a return period of 40 years, meaning a 2-3% chance of occurring annually. Extrapolating this trend back to a 1.3°C colder climate, the intensity increase is estimated at approximately 60%.
According to Professor Piet Kenabatho from the Department of Environmental Science at the University of Botswana, the country has experienced at least three extreme rainfall events in the last decade in 2017, 2021, and 2025, all occurring in mid-February.
This pattern is largely attributed to human-induced climate change. Scientists analyzed weather data and climate models using peer-reviewed methods to compare today’s climate, with approximately 1.3°C of global warming, to the cooler pre-industrial climate.
Further extending the analysis into the future, researchers assessed the impact of an additional 1.3°C of global warming from present levels. This aligns with the latest Emissions Gap Report from the United Nations Environment Programme (UNEP, 2024), which indicates that the world is on track for at least a 2.6°C temperature rise under currently implemented policies.
Dr. Joyce Kimutai, an attribution scientist, commends the efforts by WWA researchers in collaborating to focus on specific regions in their studies. She emphasizes the importance of deploying peer-reviewed methods to ensure more clarity on context-based climate issues.
Mr. Tiro Nkemelang, a researcher at the Botswana Institute for Technology Research and Innovation and a PhD candidate at the African Climate and Development Initiative of the University of Cape Town, emphasized the importance of attribution studies in understanding these events and their national impact.
“Climate change is real, and its impacts are undeniably visible. This research helps bridge the gap and underscores the need for greater investment in local weather and climate research, particularly at the intersection of climate and development. As His Excellency, President Duma Boko, stated in response to the floods, we must ‘work to better plan for these occurrences,’” said Mr. Nkemelang.
The Five-Day Rainfall Pattern in Botswana and Parts of South Africa
The five-day rainfall event, though historically significant, has shown an increasing trend over the last decade. Scientists estimate that due to rising emissions and higher temperatures, similar rainfall events today are about 60% more intense than in pre-industrial times.
This aligns with research from Working Group 1 of the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), which found increasing trends in extreme precipitation in both eastern and western Southern Africa (Seneviratne et al., 2021).
Additional studies on the five-day rainfall phenomenon, including CMIP5 models, project increases in the annual wettest day and wettest five-day period across semi-arid regions such as southern, central, and eastern Botswana at warming levels of 1.5°C and 2°C (Nkemelang et al., 2018).
Dr. Ben Clarke, a researcher from Imperial College London’s Centre for Environmental Policy, pointed to human-driven climate change as a key factor in the floods. He explained that weather records show heavier rainfall pounding southern Botswana in recent decades, a trend climate models predict will intensify moving into the future.
“This is exactly what we expect from physics, as a warmer atmosphere can hold more moisture and lead to more extreme downpours. To limit the damage, we need to cut fossil fuel emissions and adapt to a warmer climate,” said Dr. Clarke.
Scientists emphasize the need to expand drainage capacity, enforce zoning laws to limit development in high-risk areas, and upgrade critical infrastructure to withstand both present and future climate challenges.
They call for institutions and governments to adopt a comprehensive approach that integrates multi-hazard assessments into urban planning, infrastructure development, and disaster preparedness. Strengthening early warning systems and proactive climate adaptation measures will be crucial in building resilience to future extreme weather events.
