Geneva, 28 September, (Brussels Morning Newspaper) – A powerful El Niño is strengthening across the tropical Pacific, with international climate agencies warning that the event could reach exceptional intensity before the end of 2026 and influence rainfall, temperatures and extreme weather into 2027.
Pacific warming signals an unusually strong event
The US Climate Prediction Center said on 10 September that there was a greater than 90% chance of a very strong El Niño during the Northern Hemisphere autumn and winter of 2026-27.
The Niño-3.4 index reached +1.8°C in August, while sea-surface temperature anomalies exceeded +3°C in parts of the eastern equatorial Pacific. Unusually warm water also extended below the ocean surface, reinforcing the developing event.
US forecasters placed the probability of the October-December period reaching a three-month Relative Oceanic Niño Index of at least +2.5°C at 75%. Such a level would exceed previous events in the agency’s record dating to 1950.
WMO forecasts El Niño will persist into 2027
The World Meteorological Organization said in September that El Niño was firmly established and expected to strengthen further before reaching its seasonal peak.
Its forecasts indicated a near-100% probability that El Niño conditions would continue through February 2027.
UN Secretary-General António Guterres described the rapid development by saying:
“El Niño is being supersized before our eyes.”
WMO Secretary-General Celeste Saulo also highlighted the consequences already being experienced:
“We are already seeing disruption and devastation from droughts and floods.”
The WMO stresses that early forecasts give governments and humanitarian organisations an opportunity to prepare for potential climate-related emergencies.
Australian measurements show exceptional Pacific heat
Australia’s Bureau of Meteorology reported a Relative Niño-3.4 value of +2.51°C for the week ending 13 September, substantially above its +0.8°C threshold for El Niño conditions.
Climate models monitored by the Bureau indicated further warming was likely during the Southern Hemisphere spring, with most forecasting a peak above +3°C.
The Bureau said forecast values could exceed the warmest observed since reliable records began in 1950. It nevertheless cautioned that the intensity of an El Niño event does not automatically determine the severity of weather impacts in individual countries.
Powerful El Niño could alter global rainfall patterns
El Niño develops when unusually warm surface waters across the central and eastern equatorial Pacific interact with the atmosphere and alter large-scale circulation.
These changes can affect weather thousands of kilometres from the Pacific. Depending on the region and season, typical effects can include changes in drought and flood risk, abnormal temperatures and disruption to agricultural conditions.
The WMO’s September-November seasonal outlook indicated an increased probability of above-normal temperatures across almost all land areas.
Other climate systems, including conditions in the Indian and Atlantic oceans, can strengthen, weaken or modify regional impacts.
Climate agencies prepare for late-2026 peak
Forecasters will continue monitoring Pacific sea temperatures, atmospheric circulation and rainfall as the powerful El Niño approaches its expected late-year peak.
NOAA’s Climate Prediction Center is scheduled to issue its next ENSO Diagnostic Discussion on 8 October 2026, providing updated forecasts for the event’s intensity and duration.
The findings will be closely watched by governments, meteorological agencies, agricultural authorities and humanitarian organisations as preparations continue for potential climate disruption during late 2026 and early 2027.
