El Niño is expected to contribute to below-average tropical cyclone activity in the South-West Indian Ocean during the 2026-2027 season, according to WMO's Regional Specialized Meteorological Centre (RSMC) La Réunion (Météo-France) .
There is a 70% probability of below-normal activity, with 6 to 10 named storms forecast, including three to five tropical cyclones. The total includes Tropical Storm Agueda, which formed in October. An average season has 10 named storms, including five tropical cyclones.
The outlook reflects an exceptionally strong El Niño , expected to peak in November or December and persist into early 2027. Its influence on wind patterns is expected to make conditions less favourable for cyclone development.
This is combined with a negative Subtropical Indian Ocean Dipole - another climate driver which has a big regional impact.
However, a catastrophic cyclonic event can occur even during a season with low activity, so communities must remain vigilant.
Above-normal rainfall is likely in the United Republic of Tanzania, northern Madagascar, Comoros and parts of Seychelles during November 2026-January 2027. Below-normal rainfall is expected in southern and central Mozambique and parts of western Madagascar, with normal to below-normal rainfall in parts of South Africa and southern Madagascar.
Near-normal rainfall is expected in the Mascarene Islands during November-January, followed by above-normal rainfall in February-April 2027. Individual cyclones can significantly affect seasonal totals, particularly on islands.
These forecasts help disaster management and humanitarian agencies plan ahead. They were presented at an online forum on 28 October, organised by Météo-France La Réunion, WMO and the Indian Ocean Regional Intervention Platform .
