Super El Niño 2026: what it means for global weather patterns

01What makes a ‘super’ El Niño

El Niño is the warm phase of the El Niño-Southern Oscillation, a global climate phenomenon that emerges from variations in winds and sea surface temperatures over the tropical Pacific Ocean. When sea surface temperatures in the central and eastern equatorial Pacific rise significantly above average, the atmospheric circulation responds, shifting weather patterns across the globe.

A “super” El Niño is an informal designation for events where the Oceanic Niño Index (ONI) exceeds 2.0 degrees Celsius above the long-term average for at least three consecutive overlapping three-month periods. Only a handful of events in the instrumental record meet this threshold: 1982-83, 1997-98, and 2015-16. Each produced severe and widespread weather disruptions.

The 2026 event, if it reaches super status, would arrive on top of a warming baseline that has lifted global mean temperatures by more than a degree since the 1982 event. The same ONI anomaly today produces a larger absolute temperature impact than it did four decades ago, because the ocean and atmosphere are warmer to begin with.

02The science of ENSO cycles

The El Niño-Southern Oscillation operates through a coupled ocean-atmosphere feedback loop. During neutral conditions, trade winds blow westward across the Pacific, pushing warm surface water toward Indonesia and Australia while cold water wells up off South America. During El Niño, the trade winds weaken or reverse, allowing warm water to slosh back eastward.

Climate variability includes all variations in the climate that last longer than individual weather events, and ENSO is one of the most consequential modes of natural variability. Its irregular pattern means events do not follow a strict schedule, though they tend to occur every two to seven years. The occurrence of ENSO is not easily predictable, especially beyond a few months in advance.

The Southern Oscillation, the atmospheric component, is measured by the pressure difference between Tahiti and Darwin, Australia. When this pressure gradient collapses, it signals that the Walker circulation has weakened, reinforcing the oceanic warming. This coupling between ocean and atmosphere is what makes ENSO a self-sustaining phenomenon that can persist for months once established.

03Historical super El Niños and their impacts

The 1997-98 El Niño, one of the strongest on record, caused devastating floods in Peru and Ecuador, drought in Indonesia and Australia, and a mild winter in North America. Its economic toll was estimated at tens of billions of dollars globally. The event was notable for the speed at which warm water migrated across the Pacific, catching some regions unprepared.

The 2015-16 event rivaled 1997-98 in intensity and contributed to record global temperatures in 2016, which remained the warmest year on record for years afterward. Coral bleaching affected the Great Barrier Reef on an unprecedented scale, and drought-driven wildfires burned across Southeast Asia and the Amazon. The event demonstrated how El Niño acts as a multiplier on existing climate stress.

The 2023-24 El Niño, while not reaching super status, still pushed 2023 to become the warmest year in the instrumental record. Its relatively rapid transition to neutral conditions in 2024 limited some impacts but raised questions about whether the relationship between ONI and global temperature is shifting as the climate warms.

04Predicted weather disruptions by region

A super El Niño in 2026 would produce regionally specific disruptions. The western coast of South America typically experiences heavy rainfall and flooding, while southern South America sees wetter conditions. Conversely, the western Pacific — Indonesia, the Philippines, and northern Australia — faces drought and elevated fire risk.

In North America, the southern tier of the United States typically sees wetter and cooler conditions, while the northern tier experiences milder and drier weather. For the Horn of Africa, El Niño generally brings above-average rainfall during the short rains season, though the relationship is less reliable than in the Pacific basin.

India’s monsoon, which feeds more than half of the country’s cultivated land, tends to weaken during El Niño years. A super event could reduce monsoon rainfall significantly, with cascading effects on food production, reservoir levels, and rural employment across South Asia.

05Agricultural and food security implications

Agriculture is among the most climate-sensitive sectors, and El Niño disrupts production across multiple regions simultaneously. Drought in Southeast Asia affects palm oil, rice, and coffee yields. Flooding in South America can damage or benefit crops depending on timing and intensity. The simultaneous nature of these disruptions limits the ability of global markets to compensate through trade.

Food security concerns extend beyond production to access. When harvests fail in one region, prices rise globally, and import-dependent nations bear the brunt. The 2015-16 event contributed to food emergencies in several African countries, and a 2026 super event would test systems already strained by consecutive years of climate stress.

Fisheries are also directly affected. El Niño warms the waters off Peru, driving anchoveta and other species deeper or away from traditional fishing grounds. The Peruvian fishery, one of the largest in the world, can see catches fall by half during strong events, with economic consequences for the fishing industry and fishmeal markets.

06Economic costs of extreme ENSO events

The economic costs of a super El Niño extend across disaster response, agricultural losses, infrastructure damage, and public health. The 1997-98 event was estimated to have caused over 20 billion dollars in damages globally. A 2026 event, arriving at higher baseline temperatures and with more exposed infrastructure, could exceed that figure.

Insurance markets respond to ENSO forecasts, adjusting premiums and reserves ahead of anticipated losses. But many of the most affected regions have low insurance penetration, meaning costs fall directly on households and governments. The fiscal burden on developing countries, which have limited disaster response budgets, can persist for years.

Energy markets are also affected. El Niño can alter hydropower capacity in South America and change heating and cooling demand patterns in North America. Natural gas and coal prices can swing as utilities adjust, creating volatility that ripples through industrial supply chains.

07How forecasting models are improving

ENSO forecasting has improved substantially over the past two decades, but the predictability barrier — the spring period when model skill drops sharply — remains a challenge. Current coupled ocean-atmosphere models can skillfully predict El Niño several months in advance, but distinguishing between a moderate and a super event earlier in the year remains difficult.

Advances include better ocean observation networks, particularly the Tropical Pacific Observing System of buoys and Argo floats, which provide real-time data on subsurface ocean conditions. Machine learning approaches are being combined with physical models to improve probabilistic forecasts, though their reliability during extreme events is still being evaluated.

The practical value of improved forecasting depends on whether vulnerable regions can act on the information. Early warning systems, drought preparedness plans, and flexible agricultural calendars can reduce the human cost of a super El Niño, but only if the political and institutional will exists to invest before the event arrives.