WMO warns of El Niño with 80% chance in the quarter

The World Meteorological Organization warns of the formation of an El Niño event in the tropical Pacific. The probability reaches 80 percent between June and August 2026. The chance of it continuing until at least November is close to or above 90 percent. The phenomenon is expected to influence temperatures and rainfall in several regions and increase the risk of extreme weather events in the coming months.

The WMO's latest El Niño/La Niña update points to uncertainty regarding the peak intensity and the moment of greatest strength of the event. Even so, most models indicate at least a moderate El Niño, with the possibility of strong intensity.

The WMO reports that abnormally warm ocean waters in the tropical Pacific are fueling the development of the phenomenon. Between the end of April and mid-May, sea surface temperatures in the central-eastern Equatorial Pacific approached El Niño thresholds. This region serves as a reference point for monitoring.

Surface anomalies

Surface anomalies are supported by warm subsurface conditions across the tropical Pacific. Below-surface temperatures exceeded the average by more than six degrees Celsius. This heat reservoir contributes to the observed warming at the surface. The Southern Oscillation Index, an atmospheric component of El Niño, also shows a signal consistent with the development of the phenomenon.

Global temperature

The WMO states that El Niño typically raises global temperatures and alters rainfall patterns. The phenomenon also increases the likelihood of certain weather and climate extremes. Even a moderate El Niño can make heat waves, heavy rainfall, and droughts more probable in certain regions.

The Secretary-General of the WMO, Celeste Saulo, stated that governments and climate-sensitive sectors need to prepare for a potentially strong event. According to her, El Niño could worsen droughts and heavy rains and increase the risk of heat waves on land and in the ocean. The WMO cites the 2023-2024 El Niño as one of the five strongest ever recorded and reports that it contributed to the record global temperatures of 2024.

Sensitive sectors

Agriculture is among the climate-sensitive sectors cited by the WMO. The organization's update addresses governments, humanitarian agencies, and areas such as agriculture, health, energy, and water management. The document brings together consensus models from the WMO's Global Production Centers, experts from National Meteorological and Hydrological Services, and climate forecasting centers.

El Niño corresponds to the warm phase of the El Niño-Southern Oscillation. It involves warming of the ocean surface in the central and eastern equatorial Pacific. The phenomenon generally occurs every two to seven years. Its duration usually varies from nine to twelve months. Development typically begins between March and June. The peak usually occurs between November and February. The impacts on global temperature tend to become more evident in the second year after development.

The WMO emphasizes that each event presents its own evolution, spatial pattern, and impacts. The intensity, duration, time of formation, and interaction with other modes of climate variability influence the effects. Among these modes, the organization cites the Indian Ocean Dipole. Even in the neutral phase of the El Niño-Southern Oscillation, extreme events can occur.

Super El Niño

The organization does not use the expression "super El Niño." According to the WMO, this term is not part of standardized operational classifications. The organization also reports that there is no evidence of an increase in the frequency or intensity of El Niño events due to climate change. However, a warmer ocean and atmosphere can amplify associated impacts, as they increase the availability of energy and moisture for extremes such as heat waves and heavy rainfall.

Typical impacts include increased rainfall in parts of southern South America, the southern United States, the Horn of Africa, and Central Asia. They also include drier conditions in Central America, northern South America, the Caribbean, Australia, Indonesia, and parts of South Asia.

During the Northern Hemisphere summer, warm waters associated with El Niño can favor hurricanes in the central and eastern Pacific. At the same time, they can inhibit hurricane formation in the Atlantic basin. The U.S. National Oceanic and Atmospheric Administration predicts a below-normal hurricane season in the Atlantic basin this year, according to the WMO.

Climate update

The WMO also released a Global Seasonal Climate Update. The document considers the El Niño-Southern Oscillation and other climate factors, such as the North Atlantic Oscillation, the Southern Annular Mode, and the Indian Ocean Dipole. For June, July, and August, forecasts indicate a near-universal predominance of above-normal temperatures in almost all parts of the planet.

This scenario increases the risk of heat stress and combined hazards in some regions. It can also accelerate the development of drought conditions where rainfall decreases. Rainfall probabilities follow typical El Niño patterns and may contribute to a higher chance of extremes, such as increased rainfall and flooding, as well as drier and more arid conditions.