El Niño set to be 'strongest in living memory', says UK's Met OfficeScientists say the growing El Niño weather pattern is an "unprecedented event" and means 2027 is likely to be the world's hottest year on record.2 hrs ago

ByBen Rich, Lead Weather Presenter and Mark Poynting, Climate Journalist.

Key points

• Continued to the effects of human-induced climate change, the Met Office is warning that it is "very likely" to mean 2027 is the hottest year on record.
• This would be unprecedented in records going back to 1950, and probably the strongest event since the 19th century.
• "Hence, 2027 is very likely to replace 2024 as the warmest year on record."
• The El Niño event that is developing over the Pacific Ocean is projected to be the strongest in living memory, the Met Office has cautioned.
• For example, in El Niño years the southwest monsoon can deliver suppressed rainfall in South Asia – and so far in 2026 it is running well below normal.

Notably, the El Niño event that is developing over the Pacific Ocean is projected to be the strongest in living memory, the Met Office has cautioned.

For context, the powerful natural climate phenomenon pushes up global temperatures and can growth the risks of extreme weather.

There is growing evidence that weather patterns worldwide are already being affected, with below-average monsoon rains in India and suppressed hurricane activity in the Atlantic Ocean.

El Niño could put the UK at greater risk of a wet, stormy autumn.

"We should be clear that this is an unprecedented event", remarked Prof Adam Scaife, head of long-range forecasting at the UK Met Office.

"I have never seen an El Niño signal this intense in our forecasts."

El Niño is a naturally occurring weather pattern. It happens regarding every two to seven years, lasting for around a year.

Trade winds that typically blow from east to west throughout the Pacific Ocean can weaken or even reverse, allowing warm water to spread eastwards.

Heat is published from the ocean into the atmosphere, lifting global temperatures and shifting rainfall patterns.

Scientists declare an El Niño when sea surface temperatures in a key area of the Pacific are 0.5C or more above average. Current measurements show that they are well over 2C above normal.

Latest forecasts from the Met Office suggest that these temperature anomalies could exceed 3C afterwards this year as El Niño nears its peak.

Particularly high temperatures in the deeper ocean – around 8C above normal at a depth of 100m (330ft) in some places – could assist to supercharge this El Niño, essentially providing a reservoir of warm water fuel to reinforce the event.

"We have many months to go while this event continues to develop and that's one of the reasons that we have increased confidence that this will be a record-setting event, " remarked Dr Zeke Hausfather, a climate scientist at Berkeley Earth, a US research group.

Some other climate groups have projected something even stronger than the Met Office's forecast, perhaps even 4C above average.

Although it is impossible to say for sure that far back in time, if that came to pass, "It's not beyond the realm of possibility to say this might be the strongest El Niño event in 500 or even 1, 000 years, " Hausfather remarked.

Notably, the change in the distribution of heat throughout the ocean – and shifts in the wind patterns in the atmosphere above – can have wide ranging effects on the weather right throughout the globe.

No two El Niño events are the same and the impacts on weather patterns can vary. Nevertheless, there is evidence that the effects are already being felt.

Changes in wind patterns in the Caribbean and tropical Atlantic can reduce hurricane activity. So far this season there have been only three named storms.

In areas close to the tropical Pacific the influence of El Niño can be profound, with the risk of drought and bushfires in Australia and the rose threat of flooding in Peru, Ecuador and the southern United States. What effects will El Niño have on the UK's weather?

El Niño is not thought to have been a major driver of the record-breaking heatwaves that have dominated this summer.

Nevertheless it could have a greater impact on the weather during autumn and early winter, with the climbed potential for wet and stormy conditions throughout north-west Europe, including the UK.

Although the links are rather loose, perhaps counter-intuitively, El Niño can additionally rise the odds of cold weather late in the winter. 2027 "very likely" to be the hottest on record.

During El Niño events, significant heat is published from the ocean to the atmosphere.

Met Office climate scientist Dr Nick Dunstone notes this can lead to an rise in global average temperature, particularly in the calendar year after the winter peak of the El Niño.

Earlier this month, the UN's Food and Agriculture Organization cautioned that El Niño could threaten tens of millions of residents in at-risk countries with crisis-level acute food insecurity.

Taken together, the developments around el Niño set to be ' strongest in living memory' , says UK' s Met point to a situation that is still moving, and the coming days should bring more clarity.