Southern Africa is heading into a summer shaped by a forecast very strong El Niño, with the climate phenomenon having developed earlier than usual and expected to peak between October and January 2027.
The ENSO Reference Group, a group of experts from South African research institutions and agencies, said in its latest August update that the forecast of a very strong El Niño remained in place for the coming austral summer.
The group said the event was unusual because warming in the Niño 3.4 region, an important indicator of El Niño, began earlier than average.
It emphasised that the precise impacts on the region remained uncertain because every El Niño event has unique characteristics.
El Niño and La Niña are the warm and cool phases of the El Niño-Southern Oscillation (ENSO), a recurring climate pattern in the tropical Pacific that influences weather around the world.
Modelling by the University of Pretoria indicates a peak between October and January, while observations show unusually early warming in the Pacific.
“All the above metrics demonstrate the unusual nature of this El Niño event with earlier
than average warming in the Niño 3.4 region and global average records of global average SSTs [sea surface temperatures] being reported.
The group cautioned that the behaviour of each ENSO event was influenced by other oceanic and atmospheric processes, which could amplify or lessen its local effects.
“This can contribute to the amplification or amelioration of the local impacts, resulting in a significant degree of uncertainty with regard to forecasts of the impacts of the ENSO, including this 2026 El Niño.”
The group said it would provide a more detailed update on the development, the manifestation and forecast of the El Niño and its anticipated impact at the 2026 /2027 El Niño summit on 10 September.
“We will present some views on the extreme weather experienced early and late in the winter (and the dry July in the winter rainfall region) as well as the recent extreme
summer weather experienced in the northern hemisphere.”
The reference group would continue to monitor the situation and issue a formal update during the summit.