The next El Niño could be unlike any seen in modern records, with the UK Met Office warning that the developing Pacific weather pattern may become the strongest in living memory.
The event is already drawing concern from climate scientists because of its potential to push global temperatures higher and disrupt weather patterns across several continents. The Met Office says it is very likely to help make 2027 the hottest year ever recorded.
“This is an unprecedented event,” said Prof Adam Scaife, head of long-range forecasting at the Met Office. “I have never seen an El Niño signal this intense in our forecasts.”
El Niño is a natural climate cycle that normally occurs every two to seven years. It begins when the Pacific’s trade winds weaken, allowing unusually warm water to move eastwards. The ocean then releases large amounts of heat into the atmosphere, affecting temperatures, rainfall and winds far beyond the Pacific.
Current sea-surface temperatures in the key Pacific region are already more than 2 degrees Celsius above average. Met Office forecasts suggest they could rise above 3 degrees later this year as the event reaches its peak. That would be without precedent in records dating to 1950.
Scientists are also watching unusually warm water deeper beneath the Pacific surface. In some areas, temperatures around 100 metres below the surface are about 8 degrees above normal, creating a large store of heat that could strengthen the event.
Dr Zeke Hausfather, a climate scientist at Berkeley Earth, said the event still had months to develop. That, he said, has increased confidence that it could set records. Some climate researchers have forecast an even stronger event, with temperatures potentially reaching 4 degrees above average.
A warmer world, bigger consequences
Scientists caution against directly blaming climate change for the strength of El Niño.
The World Meteorological Organisation says there is currently no evidence that global warming is making El Niño events more frequent or stronger. Researchers continue to study the relationship, while historical records show that the phenomenon has varied greatly over much longer periods.
What is less disputed is the backdrop against which this El Niño is developing: the planet is already warmer because of human activity. That means the effects of an unusually strong El Niño could be felt on top of an already elevated global temperature.
The consequences could be uneven.
South Asia has already experienced weaker-than-usual monsoon rainfall in 2026, a pattern associated with El Niño years. Parts of South America and Australia may face greater risks of drought and wildfires, while Peru, Ecuador and the southern United States could see a higher risk of flooding.
The economic effects could also be significant. Previous El Niño events have disrupted crops including coffee, rice and cocoa, contributing to food-price increases and losses across global supply chains. The UN Food and Agriculture Organisation has warned that the current event could expose tens of millions of people in vulnerable countries to severe food insecurity.
Not every region will experience more extreme weather. El Niño can suppress hurricane activity in the Atlantic and Caribbean by altering wind patterns. Only three named storms had formed in the Atlantic season by the time of the report.
What it could mean for 2027
The most striking forecast concerns global temperatures.
The planet has already warmed by roughly 1.4 degrees Celsius since the late 19th century, largely because of human activities such as burning fossil fuels. El Niño can temporarily add more heat to the atmosphere as unusually warm ocean water releases energy.
That effect is often strongest in the calendar year after El Niño reaches its peak.
Dr Nick Dunstone, a climate scientist at the Met Office, said this makes 2027 “very likely” to overtake 2024 as the warmest year on record.
For Britain, the immediate effects may be less dramatic than in tropical regions. El Niño is not considered a major driver of the record heatwaves experienced during the current summer. But forecasters say it could influence conditions later in the year, increasing the chances of wetter and stormier weather across north-west Europe.
The links are not straightforward. El Niño can also raise the possibility of colder conditions later in the winter, although scientists describe that relationship as less certain.
Scientists are watching the Pacific closely. The event has not yet reached its peak. But if current forecasts hold, the coming months could offer an unusually clear test of how a powerful natural climate cycle behaves in an already warming world.
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