What WMO’s Near-Certain El Niño Forecast Could Mean for 2026–27

WMO’s latest outlook is notable for its confidence: El Niño is firmly established, is expected to strengthen into a very strong event, and has an exceptionally high likelihood of nearly 100% of persisting through February 2027. Exceptionally warm tropical-Pacific surface and subsurface waters support that outlook. 9 NOAA likewise put the chance of a very strong event above 90% during Northern Hemisphere autumn and winter 2026–27. 2

That is a major warning signal, not a forecast of identical disruption everywhere. El Niño changes the odds of seasonal heat and rainfall patterns across large regions; it does not determine whether a particular town will experience a flood, drought, heatwave or storm.

What is highly likely—and what remains uncertain

The best-supported conclusion is that the 2026–27 El Niño will continue into early 2027 and is likely to become very strong. WMO says this degree of agreement across its forecasting network is unprecedented for one of its El Niño/La Niña updates. 9

The event’s eventual peak strength, its precise timing and its local consequences are less certain. Seasonal forecasts describe probability shifts, not guarantees. Regional impacts depend on the season, local climate, other ocean-atmosphere patterns and short-term weather variability. The practical lesson is to prepare for elevated risk while continually updating decisions with local forecasts.

Why global temperatures could rise further

El Niño is the warm phase of the El Niño–Southern Oscillation, a natural climate pattern centered in the tropical Pacific that affects weather around the world. 46 A strong event adds a natural warming influence to a climate system already affected by human-driven warming.

The UK Met Office has said the combination could make 2027 the warmest year on record globally, while WMO says 2027 has the potential to be exceptionally warm. That outcome remains a projection rather than a certainty. 34

This distinction matters: El Niño is not caused by a single year of emissions, but it unfolds over an unusually warm ocean and atmospheric baseline. Research based on coral records has found that eastern-Pacific El Niño events in the past 40 years were about 36% stronger than pre-industrial events. The finding raises concern about how warming may be affecting this form of ENSO, but it does not provide a precise prediction for the final strength or local impacts of this particular event. 38

The core hazard: rainfall shifts, not one global weather pattern

A very strong El Niño can increase the likelihood of both drought and excessive rainfall—often in different places at the same time. WMO’s outlooks associate El Niño with enhanced chances of wetter-than-normal conditions in some regions and drier-than-normal conditions in others. 1819

That redistribution can create cascading risks:

• Heat and drought: Higher temperatures and rainfall deficits can reduce soil moisture, increase irrigation demand, lower reservoir inflows and intensify pressure on water supplies.
• Flooding and heavy rain: Excess rainfall can damage homes, roads, crops and water systems, disrupt travel and access to health care, and contaminate drinking-water sources.
• Agriculture and food security: Both too little and too much rain can reduce yields or disrupt planting and harvesting. Agricultural drought, water stress and food insecurity can continue for months after El Niño peaks. 33
• Energy and infrastructure: Heat raises cooling demand; drought can constrain hydropower and water-dependent operations; flooding can disrupt transport, power systems and essential services.
• Public health: Heat, floods and drought can overlap with risks to water and sanitation, infectious-disease control, nutrition and access to care. A public-health analysis for the Americas warns that exceptionally warm ocean and atmospheric conditions may amplify or modify El Niño-related drought and flood risks, even though their geography and intensity remain uncertain. 31

What regional outlooks suggest

A global El Niño forecast is only useful when translated into local planning. The available outlooks point to different risks across the locations most often highlighted in early assessments.

United States

There is no single national El Niño outcome for the United States. WMO has identified wetter-than-normal conditions as more likely in western North America south of 45°N, but risks must be interpreted by season and locality. 19 Water managers, emergency planners and utilities need locally tailored outlooks for flooding, drought, wildfire conditions, water supply and electricity demand rather than relying on a national generalization.

Puerto Rico and the Americas

Across the Americas, the concern is overlapping drought- and flood-related emergencies against an exceptionally warm global ocean and atmosphere. The public-health assessment notes that these background conditions may amplify or alter expected El Niño anomalies, making surveillance and preparedness especially important where water, health and social systems are already under strain. 31

Sudan and Uganda

The seasonal picture across the Greater Horn of Africa is complex and changes by season. For the June–September rainy season, the regional outlook identified a high likelihood of below-normal rainfall across much of the northern Greater Horn, including Sudan and Uganda. 22 For the final quarter of 2026, a later regional outlook indicated increased likelihood of wetter-than-normal conditions across the Greater Horn of Africa. 17

Those apparently different signals are not necessarily contradictory: they reflect different seasons and regional patterns. For Sudan and Uganda, the key need is continuous use of country-level advisories rather than treating “El Niño” as a single forecast for the whole year.

Why WMO is scaling up early warnings

Seasonal climate forecasts can identify broad heavy-rainfall and drought patterns one to six months ahead. WMO says that lead time can support planning in agriculture and health, government emergency protocols and the pre-positioning of humanitarian supplies. 16

For this event, WMO and national meteorological and hydrological services are strengthening preparedness and early-warning work. 21 In practice, that can mean reviewing reservoir operations, issuing crop and livestock guidance, preparing flood defenses, targeting disease monitoring and ensuring warnings reach communities exposed to the highest risks.

The aim is not to claim certainty about disasters. It is to act on unusually strong evidence that the background odds have shifted before a seasonal hazard becomes a humanitarian emergency.

The bottom line

The unusually confident forecast means governments, businesses and communities should treat the 2026–27 El Niño as a high-priority climate risk now. A very strong event would increase the chance of damaging heat, drought and heavy rainfall while adding to an already warm climate baseline. 92

But the appropriate response is not a one-size-fits-all disaster prediction. It is flexible, local preparation: use national weather-service updates, plan for both water scarcity and excess rainfall where relevant, and revise actions as seasonal forecasts narrow the regional picture.