NOAA Raises Odds of Potentially Historic El Niño for Fall and Winter 2026-27

The National Oceanic and Atmospheric Administration (NOAA) has increased the chance of an exceptionally strong El Niño developing for the upcoming fall and winter seasons, with fresh Pacific observations indicating continued intensification. Weekly Niño 3.4 has reached +2.0°C, and NOAA estimates a 75% chance that the late-2026 RONI will reach +2.5°. This event is particularly concerning as it would occur on top of an already warmer planet and unusually warm oceans, potentially intensifying heat extremes, rainfall disruption, coral bleaching, and pressure on food and water systems.