Increased rainfall and storms are forecast to hit the UK this autumn as a result of an “unprecedented” El Niño weather pattern developing over the Pacific Ocean, the Met Office has warned.
The El Niño event is likely to be the strongest for more than 100 years. Prof Adam Scaife, the head of long-range forecasting at the Met Office, said a typical El Niño involves Pacific sea temperatures rising by more than 1C, with 2C being a “really big event.” This year, Pacific sea temperatures are set to rise by 3C.
“We’re expecting the biggest El Niño for over a century, peaking at something over 3C. That is unheard of in modern climate records,” Scaife told BBC Radio 4’s Today programme.
The Impacts
Scaife said the impacts would be felt worldwide, adding they would be “particularly strong throughout the tropics, where we expect really severe droughts in places like South America and the west Pacific.”
“There are wave-like disturbances that come out from the tropics and affect places like the UK. So we already see signals for increased rainfall and storminess in the autumn here in the UK around November time,” he said.
There is also a heightened risk of drought in southern Africa and north-east Australia, while north-western Europe – including the UK – is likely to experience wetter and stormier conditions, the Met Office said.
Temperature Rise
El Niño will also drive an increase in global average temperature, with 2027 forecast to be the warmest year on record.
Dr Nick Dunstone, a science fellow at the Met Office, said: “During large El Niño 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 Niño.”
“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 preindustrial period.”
UK Drought Context
The warning comes as the UK faces severe water shortages. A series of record heatwaves and a lack of rainfall in recent months has brought the driest July in 190 years and has pushed almost three-quarters (71.3%) of England, and all of Wales, into drought.
Reservoir levels have fallen to 62.6% – 16.3% lower than expected for this time of year, according to Defra.
After an emergency meeting to discuss the heatwave last week, Andy Burnham said: “We might be in for a wet autumn and winter straight after this, because of El Niño.”
Drought Persists
The National Drought Group, which brings together the Met Office, regulators, government, water companies, farmers, scientists, and conservation organisations, said this week’s rainfall and cooler temperatures will not make any significant impact on current water scarcity.
It also warned that drought conditions could persist into the new year, as current forecasts do not suggest this autumn will have the amount of rainfall required to drive recovery before December. The panel revealed it was moving from monthly to weekly meetings to step up its coordinated response to extreme weather.
The Bottom Line
The UK will face increased rainfall and storms this autumn as the strongest El Niño in over a century develops over the Pacific Ocean. The Met Office warns of severe droughts in the southern hemisphere and a rise in global temperatures, with 2027 forecast to be the warmest year on record. The UK is already in drought after the driest July in 190 years, and the National Drought Group warns that current rainfall will not be enough to end water scarcity.
