The World Meteorological Organization (WMO) warns that the probability of an El Niño episode between this month and August is 80%. According to the UN agency, although there is still some uncertainty regarding the maximum intensity and peak time, most forecast models suggest that it will be at least of moderate intensity – and possibly strong.

Temperatures above average

The probability of it continuing until at least November is close to or above 90%, says a note from "UN News". The latest update released by the agency indicates that the risk of extreme weather events has increased in the coming months. Above-average temperatures are predicted across almost the entire planet from this month until August. El Niño typically increases global temperatures and favors more extreme weather and precipitation patterns. The Secretary-General of the United Nations, António Guterres, says that "the science is clear: El Niño is coming to our doorstep in the coming months with 90% certainty." "The world must treat it as the urgent climate warning that it is. El Niño conditions will further intensify global warming. Its impacts will be more severe, spread further, and cross borders with devastating speed," he states.

Dependence on fossil fuels

According to the Secretary-General, “the only effective response is climate action commensurate with the crisis – ending dependence on fossil fuels, accelerating the transition to renewable energy, protecting the most vulnerable and ensuring early warning systems for all.” The statement says that El Niño conditions are developing and are expected to influence global temperature and precipitation patterns, increasing the risk of extreme weather events in the coming months.

Prepare for a major event.

The WMO's message is clear: the time to make informed decisions, plan, and prepare is now. Celeste Saulo, WMO Secretary-General, states that "we need to prepare for a potentially strong El Niño event, which will exacerbate droughts and intense rainfall and increase the risk of heat waves both on land and in the oceans." "The most recent El Niño, in 2023-2024, was one of the five strongest ever recorded and contributed to the record global temperatures observed in 2024," she said.

Monitoring reference

Between late April and mid-May, sea surface temperatures in the central-eastern Equatorial Pacific – an area used as a monitoring reference – approached the characteristic thresholds of El Niño, according to observations from different platforms used by the WMO. These increasing surface anomalies are being fueled by exceptionally warm conditions in the subsurface layers of the tropical Pacific, with temperatures more than 6°C above average, forming a substantial heat reservoir that contributes to the observed surface warming. Meanwhile, the Southern Oscillation Index – an atmospheric component of El Niño – also shows signs consistent with the development of the phenomenon.

Early warnings save lives.

According to the agency, advanced forecasts help in preparing to protect lives and livelihoods. “The WMO community will carefully monitor conditions in the coming months to support decision-making by governments, humanitarian agencies, and climate-sensitive sectors. Early seasonal forecasts and early warnings are crucial to saving lives and reducing the impacts on our economies and communities,” states Celeste Saulo.

How does it happen?

El Niño is characterized by warming ocean surface temperatures in the central and eastern equatorial Pacific. It generally occurs every two to seven years and lasts about nine to twelve months. It typically begins to develop between March and June and reaches its peak intensity between November and February, with its effects on global temperatures usually being most pronounced in the second year after its development. The UN agency explains that the effects of each El Niño event or the La Niña phenomenon – which tends to cool temperatures – vary according to its intensity, duration, time of year it develops, and its interaction with other modes of climate variability. Not all regions of the world are affected, and even within the same region the impacts can differ. Furthermore, extreme weather events can occur even when El Niño is in a neutral state.

Climate change

The intensity of an event is extremely important, whether it is classified as weak, moderate, strong, or very strong. Even a moderate El Niño increases the likelihood of some extreme weather events. The agency does not use the term "super El Niño" because it is not part of the standardized operational classifications. There is no evidence that climate change increases the frequency or intensity of El Niño events. However, it can amplify their impacts, as a warmer ocean and atmosphere provide more energy and moisture for extreme events such as heat waves and heavy rainfall.

Typical impacts

Each El Niño episode is unique in its evolution, spatial distribution, and impacts. However, the phenomenon is often associated with, for example, increased rainfall in parts of southern South America, the southern United States, regions of the Horn of Africa, and Central Asia. It is also associated with drier conditions in Central America, northern South America, the Caribbean, Australia, Indonesia, and parts of South Asia. The agency also reported that, during the Northern Hemisphere summer, the warmer waters associated with El Niño can favor the formation of hurricanes in the central and eastern Pacific, while hindering hurricane formation in the Atlantic basin. Therefore, the U.S. National Oceanic and Atmospheric Administration (NOAA) predicts a below-average hurricane season in the Atlantic this year. Updates on El Niño are the world's most reliable source of information for governments, humanitarian agencies, and climate-sensitive sectors such as agriculture and health. They are based on a consensus of models from the WMO Global Production Centers, experts from national meteorological and hydrological services, and climate forecasting centers around the world. 

This text was translated by machine from Brazilian Portuguese.