2026 is going to be renowned for the development of the largest El Niño in living memory and what is probably the largest such event since the 19th century.

Analysis of historical data and computer simulations highlight the anomalous global rainfall patterns from El Niño, these are also well documented in a variety of impacts and humanitarian studies which detail the more sector-specific impacts. The Indian summer monsoon is one of the regional weather patterns affected as El Niño grows and it is already running well below normal rainfall. Other regions at risk of low rainfall include Central America, west Pacific nations and tropical South America. El Niño also affects tropical cyclones and suppresses Atlantic hurricanes by increasing wind shear in the tropical Atlantic. Consistent with this, there have only been three storms so far this season, but it only takes one large hurricane to lead to devastating impacts. The El Niño is now growing towards its peak in winter, and the impacts will affect not only the tropics but also the mid latitudes and so southern Africa and north-east Australia are expected to be at heightened risk of drought. The Met Office expects the influence of El Niño to start to increase the chances of wetter, stormier conditions for NW Europe, including the UK, in the coming autumn and early winter.

“Cool” years are now hotter than the “warm” years of the past: tracking global temperatures through El Niño and La Niña – publication