An "unprecedented" El Niño event developing in the Pacific Ocean could trigger the hottest year on record worldwide while leaving the UK increasingly battered by rain and severe storms over the upcoming autumn and winter seasons, forecasters have warned.
Unprecedented Ocean Warming
El Niño is declared when tropical eastern Pacific sea temperatures rise 0.5C above the long-term average. The Met Office projects this natural oceanic warming will exceed a staggering 3C in the coming months, making it "the largest since the 19th century."
While creating a heightened risk of drought in the tropics, southern Africa, and north-east Australia, it leaves north-western Europe - including the UK - likely to experience wetter, stormier conditions.
Met Office Experts Warn of Record Heat
Professor Adam Scaife, head of long range forecasting at the Met Office, said: "We should be clear that this is an unprecedented event. I have never seen an El Nino signal this intense in our forecasts."
He added: "A typical El Nino leads to an equatorial Pacific sea-surface temperature rise of between one to 2C, with 2C being a really big event. This implies that if the forecast is accurate – and other forecast systems show similar extreme values – then 2026 will far exceed our recent experience of El Nino and its worldwide climate influences."
The phenomenon also drives global average temperatures up, with 2027 forecast to become the warmest year on record. Met Office Science Fellow Dr Nick Dunstone explained: "During large El Nino events significantly more heat is released from the ocean to the atmosphere leading to an increase in global average temperature, particularly in the calendar year following the winter peak of the El Nino.
"Hence, 2027 is very likely to replace 2024 as the warmest year on record and be another year to temporarily exceed plus 1.5C above the pre-industrial period."
UK Faces Stormy Autumn and Winter
Professor Stephen Belcher, the Met Office's chief of science and technology, added: "This summer we have experienced heat waves across Europe reminding us of the effects of climate change, this large El Nino is a reminder that natural variations in the climate system are also at play, adding to the stresses of climate change."
The stormy forecast follows an unprecedented string of heatwaves and the driest July in 190 years, which pushed 71.3% of England and all of Wales into drought, straining water systems, farming, and infrastructure. Defra revealed reservoir levels have fallen to 62.6%-16.3% lower than expected.
Following an emergency meeting, Prime Minister Andy Burnham warned: "We might be in for a wet autumn and winter straight after this, because of El Nino and some of the issues there, which was reported to Cobra."
Heavier showers recently hit parts of the country, with Morecambe, Lancashire receiving 52.5mm of rain in 24 hours - a third of the region's average summer rainfall between June 1 and August 18 (156mm). Pevensey Bay in East Sussex recorded 32mm.
The downpours raised flash flooding fears as water hit parched ground. The National Drought Group warned that current rainfall will not resolve water scarcity and drought conditions could persist into the new year. The panel announced it is shifting from monthly to weekly meetings to step up its response.
The heavy rain follows extreme heat, including a record 38.1C logged at London's Kew Gardens on August 13. Provisionally, August 14 was a record-breaking 10th day in 2026 exceeding 35C, while 2026 became the first year on record with three separate days reaching 37C.
The National Fire Chiefs Council confirmed a record 1,132 wildfires have been documented across England and Wales so far this year, including a West Midlands blaze in Stourbridge that destroyed 19 homes.
