Met Office warns developing El Niño could be strongest in living memory

The UK's Met Office has warned that the El Niño event currently developing over the Pacific Ocean is likely to be the strongest in living memory. This natural climate phenomenon raises global temperatures and increases the risk of extreme weather.

Combined with human-caused climate change, the Met Office says it is very likely that 2027 will become the hottest year ever recorded globally. Evidence is already growing that weather patterns are being affected, with monsoon rainfall in India running below average and hurricane activity in the Atlantic suppressed. The UK itself faces a heightened risk of a wet and stormy autumn.

Professor Adam Scaife, head of long-range forecasting at the Met Office, described the event as unprecedented, saying he had never before seen such an intense El Niño signal in the forecasts. While there is no clear evidence that climate change itself is intensifying El Niño events, their weather impacts become more extreme in a warmer world.

An El Niño is declared when sea surface temperatures in a specific Pacific region rise 0.5C or more above average. Current readings already exceed 2C above normal, and Met Office forecasts suggest the anomaly could pass 3C as the event nears its peak later this year — a level unmatched in records dating back to 1950, and likely the strongest since the 19th century.

Unusually high temperatures have also been recorded deeper in the ocean, with readings around 100 metres down running roughly 8C above normal in some locations, potentially acting as a reservoir of energy that intensifies the event further. Dr Zeke Hausfather, a climate scientist at the US research group Berkeley Earth, said that with several months still left for the event to develop, confidence is growing that it will set a record. Some other climate research groups project an even stronger outcome, potentially up to 4C above average — which Hausfather said could make it the strongest El Niño in 500 or even 1,000 years, though confirming that far back is impossible.