Overview
- In mid-October, NOAA and other agencies upgraded forecasts to place near-certain odds on an extremely strong El Niño through December and better than 80 percent odds it will persist into February–March 2027.
- Copernicus and other monitors reported record sea-surface temperatures in September, including an all-time high of 29.70°C in the Niño3.4 Pacific region and a global monthly ocean average that topped previous records.
- Warmer oceans and weakened Pacific trade winds are already changing atmospheric circulation, increasing the likelihood of heavier storms in some regions, droughts in others, and higher tropical cyclone activity in parts of the Pacific.
- Humanitarian and health assessments warn of major harm: UNICEF estimates more than 347 million children will be exposed to drier or wetter conditions linked to El Niño and the Climate Impacts Lab projects hundreds of thousands of excess heat deaths.
- Scientists say long-term warming likely amplifies El Niño’s effects even as attribution at event scale remains active research, and they expect this episode to inform future models and trigger preparedness actions from governments and aid agencies.