Extreme rainfall and floods in southern Africa in January 2026 -associated circulation patterns and role of climate change

In early 2026, an exceptional extreme weather events struck Southern Africa. Following heavy and persistent rains, rivers within the region exceeded their alert levels, causing large-scale flooding in South Africa, Mozambique, Zimbabwe and Eswatini. In January 2026, Mozambique’s National Institute of Meteorology (INAM) reported that several regions received record-breaking 24-hour rainfall, surpassing their annual averages. Notably, Gaza (Massangena station) recorded 271.9 mm on January 11, Maputo (Maputo Observatory) saw 213 mm on January 19, and Inhambane (Massinga station) reached 253 mm on January 10. The combination of very intense rainfall over a short period, together with high vulnerability and exposure, led to the worst flooding in Mozambique in 25 years. This led to severe socioeconomic losses, characterized by loss of life, casualties, and extensive damage to critical infrastructure in the region. At seasonal timescales, large parts of the study regions experienced record-breaking surface weather associated with the influence of La Nina setting up favourable circulation patterns for heavy rainfall. This study analyses the atmospheric and oceanic patterns linked to the event, as well as the influence of climate change, using reanalysis and gridded observational datasets. Using a probabilistic attribution approach, we found that the heavy rainfall was an exceptionally rare event in today’s climate, characterized by a high local return period. Furthermore, human-induced climate change and the weak La Niña increased the intensity and frequency of events of this magnitude. This study contributes to an improved process-understanding of extreme weather events in the region with implications for adaptation and disaster risk management.