The 2026–27 El Niño

The story so far

As of September 23, 2026

El Niño for 2026–27 is now firmly established and strengthening. The latest global update says it is near certain to persist through February 2027 and to peak late this year as a very strong event. Sea surface temperatures in the eastern equatorial Pacific are more than 3.6 Celsius above average, with key monitoring regions already above the +2.0 threshold used for very strong classification. This is the most unequivocal persistence guidance yet issued for an El Niño by the World Meteorological Organization, reflecting rare agreement across major forecasting centers.

What that adds up to is a powerful Pacific warming poised to reshape rainfall and temperature patterns worldwide for the next several months. With oceans already running unusually hot, the added El Niño heat makes new global temperature records in 2027 more likely. A new analysis by the Climate Impact Lab estimates about 451,000 additional heat‑related deaths worldwide by February 2027, with the largest increases expected in parts of the Global South; India’s projected share is about 15,800, and Nigeria and several Southeast Asian countries are also flagged for sharp rises.

The physics explain the map of concern. El Niño is a periodic warming of surface waters in the central and eastern tropical Pacific that shifts the jet stream, the high‑altitude wind belt that steers storms. Very strong events raise the odds of wetter winters along the U.S. Gulf Coast and Southeast and drier, warmer conditions over parts of the northern U.S. and Canada. Around the Pacific Rim, flood risk increases in Peru and Ecuador while drought risk rises in parts of Australia and Indonesia. These are shifts in odds, not guarantees for any given week.

The story has moved from detection to preparation. Latin American governments have begun ramping up plans, South Africa’s weather service is warning of severe heat with below normal rainfall, and island states such as Mauritius are assessing water and agriculture strain ahead of summer. A positive Indian Ocean Dipole, a separate swing in Indian Ocean temperatures that can push rain toward East Africa and away from Australia, is also in play, which puts a premium on local planning as the event builds toward its year‑end peak. The mortality projection turns this from a weather outlook into a test of public health and basic services, especially where heat exposure, power reliability and water access will decide outcomes.