2026–27 El Niño Could Be Strongest in Living Memory, Met Office Warns

That is why the agency has used unusually strong language. Its comparison with the 19th century is a historical assessment, not a claim that the precise strength has already been measured: the most extreme part of the event is still ahead, and forecasts can change as new observations arrive.

When is El Niño expected to peak?

The strongest conditions are expected during the 2026–27 Northern Hemisphere autumn and winter, with wider global temperature effects likely to be felt into 2027. The timing reflects a familiar feature of El Niño: the ocean event and its influence on global average temperatures do not necessarily reach their maximum at exactly the same time.

The Met Office’s longer-range outlook already points to a heightened chance of El Niño conditions in the central tropical Pacific, particularly during 2027 and 2028. It says an El Niño developing toward the end of 2026 increases the likelihood that 2027 becomes the next record-breaking year.

These are probability-based projections, not guarantees. The final peak depends on how the Pacific ocean and atmosphere continue to interact, as well as on shorter-term weather variability.

Why could 2027 become the hottest year on record?

El Niño temporarily transfers heat from the tropical Pacific into the atmosphere and changes the distribution of heat and rainfall across the planet. When that natural pulse occurs on top of long-term human-caused warming, global average temperatures can rise further.

The Met Office’s warning is therefore about the combined effect of two factors:

• Natural variability: a potentially exceptional El Niño could add a short-term warming boost.
• Human-caused warming: the world is starting from a substantially warmer baseline than in earlier El Niño events.

The result could be a new global temperature record in 2027. The Met Office’s language—“very likely”—describes a high-probability forecast, not certainty.

What could it mean for the UK?

The Met Office expects El Niño’s influence to favour a wetter and stormier UK autumn and winter. That is a seasonal tendency, not a prediction of every individual storm or a precise rainfall total for every location.

El Niño does not determine the UK’s weather on its own. Other atmospheric patterns and local conditions can strengthen, weaken or redirect its influence. The most useful interpretation is that the event may shift the odds toward unsettled conditions rather than guarantee a uniformly wet winter.

Where are the biggest humanitarian risks?

The World Food Programme estimates that the strengthening event could push at least 49 million additional people into acute food insecurity by the end of 2027. Its analysis covers 45 countries and projects that the total number of people facing acute food insecurity could reach 274 million.

The risks are greatest where communities are already exposed to poverty, conflict, fragile food systems or repeated climate shocks. WFP identifies parts of Central America and southern Africa among the regions facing particularly serious exposure.

El Niño can produce very different outcomes in different places: drought in some regions, destructive rainfall and flooding in others. Those shocks can reduce harvests, disrupt livestock and water supplies, damage infrastructure and raise pressure on food markets. The eventual humanitarian impact will depend not only on the strength of the event, but also on local vulnerability and how early authorities can act.

What preparedness can do

WFP and its partners are using climate forecasts and early-warning systems to support anticipatory action before droughts, floods or storms cause their worst damage. Planned measures include protecting livelihoods, pre-positioning assistance and helping vulnerable communities prepare for likely shocks.

Early action cannot prevent El Niño, but it can reduce the cost of responding after crops, homes, income or infrastructure have already been lost. The scale of the warning is a reminder that climate forecasting is most valuable when it is connected to practical decisions on the ground.

The key caveat: this is still a forecast

The evidence points to an unusually strong and rapidly developing El Niño, but the headline figures should not be treated as settled observations. A forecast of more than 3°C is a projection of the event’s possible peak, and regional outcomes will vary.

The most defensible conclusion is that the 2026–27 event has an unusually large range of potential consequences: a higher chance of global record heat, wetter and stormier conditions for the UK, sharply contrasting rainfall risks around the Pacific, and serious pressure on food security in vulnerable countries. The strength of the warning comes from the exceptional model signal and the warmer climate in which this El Niño is forming—not from certainty about every future outcome.