Met Office Warns of Record-Strength El Niño

El Niño is a natural pattern that returns every two to seven years and lasts about a year. The trade winds that usually blow east to west across the Pacific weaken, or even turn around, letting warm water spread eastwards. Heat then escapes into the air, raising global temperatures and moving rainfall to new places. The deeper ocean is unusually warm too, roughly 8C above normal 100 metres down, which gives the event extra fuel. Dr Zeke Hausfather, a climate scientist at Berkeley Earth, said months of growth still lie ahead, and confidence in a record is rising.

The effects are already visible. India's summer monsoon is well below normal, and the Atlantic has produced only three named storms this season. The Met Office says that, with human-caused climate change, the event makes 2027 very likely to replace 2024 as the warmest year on record. Britain may face a wetter, stormier autumn, Australia a drought, and Peru, Ecuador and the southern United States floods. The forecasting service OpenSnow expects above-average snow in California and Nevada, although the last very strong El Niño, in 2015-2016, ended near normal at Lake Tahoe.