The El Niño weather phenomenon is expected to intensify significantly in the coming months and is almost certain to persist until February, according to the World Meteorological Organisation (WMO).
El Niño is a naturally occurring climate pattern that raises sea surface temperatures in the central and eastern equatorial Pacific, triggering changes in global wind, pressure and rainfall patterns.
WMO Secretary-General Celeste Saulo said the phenomenon could become stronger than any El Niño recorded since systematic monitoring began four decades ago.
“If this trajectory continues, it may be stronger than anything since our monitoring began,” Saulo told reporters in Geneva.
The WMO said El Niño was expected to reach its peak towards the end of the year, while its effects on global climate could continue into 2027.
Warmer ocean temperatures release heat into the atmosphere gradually, potentially contributing to higher global temperatures in the following year.
The powerful El Niño event of 2023-24 contributed to 2024 becoming the warmest year on record. Saulo warned that another global temperature record could be set as the current El Niño intensifies.
“El Niño is firmly established and will intensify into a very strong event in the coming months,” the WMO said, warning of increased risks of floods, droughts and extreme heat.
Although El Niño is a natural climate phenomenon and is not caused by climate change, scientists say it can intensify the effects of global warming and contribute to more extreme weather.
UN Secretary-General Antonio Guterres described the phenomenon as being “supersized” and warned that rising temperatures were pushing the planet into increasingly dangerous territory.
Saulo warned that the unusually strong El Niño could have severe consequences for communities and economies worldwide.
“We are already seeing disruption and devastation from droughts and floods, and we expect these impacts to increase as El Niño intensifies,” she said.
She urged disaster management authorities and climate-sensitive sectors, including agriculture, health, energy and water, to prepare for the potential impacts.
El Niño typically occurs every two to seven years and lasts between nine and 12 months. It alternates with La Niña, its cooler counterpart, with neutral conditions occurring between the two phases.
The WMO said exceptionally warm ocean conditions across the tropical Pacific were expected to drive further strengthening of the current El Niño.
The agency classifies El Niño events as weak, moderate, strong or very strong, with the current phenomenon expected to reach the highest category.
The WMO said there was an exceptionally high likelihood, close to 100 per cent, that El Niño would continue through February.
El Niño can influence weather and climate patterns thousands of kilometres away from the tropical Pacific. Major events have previously been associated with droughts in parts of the Amazon, Indonesia and Australia, disrupted monsoon patterns in India and significant changes in rainfall across tropical regions.
For September to November, WMO forecasts indicate a heightened likelihood of above-normal temperatures across almost all land areas. Rainfall patterns are also expected to reflect the typical atmospheric response associated with a strong El Niño.
The sea surface temperature index used to measure El Niño conditions in the central and eastern equatorial Pacific rose to an average 1.5 degrees Celsius above normal between May and July.
Weekly measurements from late July to mid-August ranged between 2.2°C and 2.6°C above average, indicating that the phenomenon was continuing to intensify.
In some parts of the Pacific, temperatures below the ocean surface were more than 8°C above average during July and early August, highlighting the unusually warm conditions driving the current El Niño event.
