GENEVA, Switzerland – The United Nations’ World Meteorological Organization (WMO) has issued an updated forecast confirming a steeply elevated probability that the climate-altering El Niño phenomenon will emerge by the third quarter of 2024, bringing with it a sharply increased threat of catastrophic extreme weather events across the globe. In its quarterly update on El Niño-Southern Oscillation (ENSO) conditions released Tuesday, the agency confirmed that model data from its global collaborative forecasting network shows an 80% likelihood that El Niño will fully develop between June and August, with the probability climbing to 90% or higher by the end of November 2024.
El Niño is a naturally occurring climate pattern defined by above-average sea surface temperatures across the central and eastern equatorial Pacific Ocean, which triggers cascading shifts in global atmospheric pressure, wind patterns, and rainfall distribution. The phenomenon follows a cyclical pattern, recurring every two to seven years and typically persisting for 9 to 12 months, oscillating between its cool counterpart La Niña and neutral ENSO conditions in between cycles. Most current forecasting models indicate that the upcoming 2024 El Niño will be at least moderate in strength, with a significant possibility that it will develop into a strong event.
As of late April through mid-May 2024, WMO monitoring shows that sea surface temperatures in the central-eastern equatorial Pacific – the key reference region for tracking ENSO conditions – are already approaching the established threshold for El Niño. Below-surface ocean temperatures in the region are even more anomalous, measuring more than 6 degrees Celsius above long-term averages. The atmospheric indicator for ENSO, the Southern Oscillation Index, also aligns with the ongoing development of El Niño conditions.
WMO Secretary-General Celeste Saulo emphasized that global communities must prioritize immediate preparedness to mitigate the harmful impacts of the approaching event. Saulo noted that El Niño is likely to exacerbate existing climate stressors, amplifying the severity of droughts, intense rainfall events, and heatwaves across both terrestrial and marine ecosystems. Even a moderate El Niño, she added, is enough to substantially raise the probability of record-breaking weather and climate extremes.
The most recent El Niño event played a key role in pushing global temperatures to new historic highs: 2023 became the second-warmest year ever recorded, while 2024 surpassed all previous records to reach an average global temperature 1.55 degrees Celsius above the pre-industrial baseline of 1850-1900.
While the WMO confirms there is currently no conclusive evidence that human-caused climate change increases the frequency or intrinsic intensity of El Niño events, researchers have established that anthropogenic warming amplifies the damaging impacts of El Niño. A pre-warmed global ocean and atmosphere hold greater amounts of energy and moisture, creating conditions that supercharge extreme weather events such as heatwaves and intense downpours.
United Nations Secretary-General António Guterres framed the impending El Niño as an urgent call to action for global climate action. “El Niño is arriving on our doorstep,” Guterres said in a prepared video message. “The world must treat it as the urgent climate warning it is. El Niño conditions will pour fuel on the fire of a warming world. The only effective response is climate action equal to the crisis — ending the addiction to fossil fuels, accelerating the shift to renewables, protecting the most vulnerable, and delivering early warning systems for all.”
To date, 128 countries have established fully functional multi-hazard early warning systems, part of a UN-led initiative to achieve universal coverage for all nations by the end of 2027. Early advance warning of El Niño’s onset and intensity is designed to enable targeted preparedness across climate-sensitive sectors including agriculture, water resource management, energy, and public health, reducing harm to communities and economic disruption.
Saulo added that El Niño’s impacts extend far beyond immediate weather disruptions, creating cascading risks that touch global trade, economic stability, and human security. “These go from variability of the climate, into the economy and security of the people. That’s why this information is so relevant and so important,” she told reporters in Geneva.
Forecasts for the June to August 2024 period project nearly global above-average surface temperatures, increasing the risk of overlapping climate hazards and accelerating drought development in regions that see reduced rainfall during El Niño. While El Niño typically reaches its peak intensity between November and February, the full temperature spike associated with the event often emerges later in the cycle, and more refined forecasts for onset and strength are expected next month.
Regional climate projections paint a clear picture of targeted risk across vulnerable regions: the northern Greater Horn of Africa is expected to see below-normal rainfall during its critical June-September rainy season; South Asia is projected to experience below-average monsoon rainfall; and Central America is likely to face warmer, drier than average summer conditions. For the Atlantic and Pacific hurricane seasons, El Niño’s warm ocean waters tend to fuel more intense hurricane activity in the central and eastern Pacific, while suppressing storm development in the Atlantic during the Northern Hemisphere summer.