El Niño 2026‑27 Expected to Reach ‘Very Strong’ Strength, Prompting Global Preparedness Push

Warm Pacific waters are driving a rapid intensification of the current El Niño, which forecasters now expect to become “very strong” by the end of 2026. Subsurface temperatures in parts of the Pacific were measured more than eight degrees Celsius above normal during July and early August, providing a deep heat reservoir. The Niño 3.4 index, a key indicator of central‑tropical Pacific warmth, averaged 1.5 °C above normal from May through July, rose to 2 °C in July, and peaked at about 2.6 °C in late July‑mid‑August. While El Niño is a natural cycle, the already exceptionally warm oceans—linked to greenhouse‑gas‑driven climate change—create a hotter baseline that can magnify the event’s impacts.

From September through November 2026, forecasters anticipate above‑normal temperatures across nearly the entire Earth’s surface. The classic El Niño rainfall pattern will bring heightened chances of heavy rain and flooding in some regions, while other areas face intensified drought. Overlapping climate drivers, such as a positive Indian Ocean Dipole and unusually warm tropical Atlantic waters, add uncertainty to country‑specific forecasts but collectively signal a period of heightened risk for communities and economies worldwide. Vulnerable sectors—including agriculture, public health, energy and water supplies—are expected to feel the strongest pressure.

In response to the unprecedented forecast, the World Health Organization has launched its first‑ever large‑scale mobilisation with national weather agencies to strengthen forecasts and early‑warning systems. The effort aims to give governments and humanitarian actors the data needed to protect agriculture, health services, water infrastructure and energy provision as the El Niño intensifies. UN Secretary‑General António Guterres warned that the planet is in “uncharted waters” as the event grows, while WMO head Celeste Saulo stressed that “exceptional El Niño demands exceptional preparedness and response.”