Super El Niño: Inside the 2026 Event Rewriting the Record Books

Rain falls in Asbury Park, New Jersey. A very strong El Nino could cause more rainy days on the Jersey Shore this year. (Andrew Mills /The Star-Ledger)

As of June 2026, the tropical Pacific is undergoing a rapid shift. The National Oceanic and Atmospheric Administration (NOAA)'s Climate Prediction Center has issued a formal El Niño Advisory, confirming that El Niño conditions are present and expected to strengthen into the winter of 2026-27. Sea surface temperature anomalies in the Niño 3.4 region reached +0.48°C during March-May, climbed to +0.94°C by May, and hit +1.7°C in the latest weekly reading, centered on June 17. For context, current values are almost twice what was observed at the same point in 2023, during the last major El Niño's development. NOAA forecasters now give a 63% chance that sea surface temperatures in the Niño-monitored region will exceed 2.0°C, a threshold that would make this a historic event.

This begs the question: what is actually happening beneath the surface? El Niño and La Niña are the warm and cool phases of a natural cycle known as ENSO, driven by shifting trade winds and ocean temperatures across the equatorial Pacific. During El Niño, those winds weaken and warm water piles up in the eastern Pacific instead of the west, producing droughts in some regions and floods in others. This cycle has existed for millennia, but climate change is beginning to distort it. Rising baseline ocean temperatures mean El Niño events now build on top of an already-warmer ocean, pushing anomalies higher and making swings between El Niño and La Niña more destructive. A recent economic analysis estimated that the current El Niño cycle alone could cost the global economy $3.4 trillion, a figure researchers expect to climb toward $84 trillion by the end of the century as these cycles intensify.

The top panel shows the time series of the Oceanic Niño Index (ONI), which is the seasonal average of sea surface temperature anomalies in the Niño-3.4 region of the east-central equatorial Pacific Ocean. ONI values are also provided in this table and here. The bottom panel shows the Relative Oceanic Niño Index, which can be found here. Both indices show all three-month average (seasons) overlapping starting in December-February (DJF) 1949-50 to DJF 2020-21. Red shading shows El Niño episodes and blue shading shows La Niña episodes (thresholds must be exceeded for at least 5 consecutive, overlapping seasons). NOAA Climate.gov figure using data from NCEI ERSSTv5. 

In response, scientists and policymakers are racing to improve both prediction and preparedness. NOAA recently adopted a new Relative Oceanic Niño Index (RONI), which strips out the long-term warming trend to give a clearer read on the actual strength of an ENSO event, rather than one inflated by climate change itself. Separately, researchers at the Potsdam Institute for Climate Impact Research have pioneered climate-network and complexity-based forecasting models that can flag the onset of an El Niño roughly a year in advance, well ahead of traditional models. On the policy side, the World Meteorological Organization continues to push its Early Warnings for All initiative, aiming to get ENSO-linked drought and flood alerts into the hands of vulnerable communities before disaster strikes rather than after.