Super El Niño Threatens 50 Million People, UN Warns

The world is staring down one of the most powerful El Niño events ever measured. The World Meteorological Organization announced on September 3 that El Niño is now firmly established and expected to strengthen into a "very strong" event before peaking toward the end of 2026. Forecasts from the agency's global producing centres put the likelihood that it will last through February 2027 at nearly 100 percent — the first time a WMO El Niño/La Niña Update has ever been that unequivocal.

El Niño is a periodic warming of sea surface temperatures across the central and eastern tropical Pacific, driven by weakening trade winds. It occurs naturally every two to seven years and reshapes rainfall and temperature patterns thousands of miles from the Pacific, bringing floods to some regions and drought to others. This time, the heat stored in the ocean is running far beyond the usual script. The Niño 3.4 index — the benchmark measurement — climbed from an average of 1.5°C above normal between May and July to between 2.2°C and 2.6°C above average by mid-August, according to WMO data reported by Meteorological Technology International. Subsurface temperatures in parts of the tropical Pacific exceeded 8°C above average during July and early August.

At a Geneva press conference on September 3, WMO Secretary-General Celeste Saulo said that if the current trajectory continues, the event could be "stronger than anything" measured since monitoring began — "literally off the charts" used over the past four decades, according to Reuters. In the WMO's official statement, Saulo warned that "El Niño in Spanish means boy child – but it has the potential to deliver a massive blow to communities and economies across the world," adding that droughts and floods were already causing "disruption and devastation" and that those impacts would increase as El Niño intensifies.

What a very strong El Niño brings

A very strong El Niño can significantly shift global rainfall and temperature patterns, fueling floods, droughts and extreme heat — and in some years, more intense typhoons. The damage is not hypothetical. Reuters reported that this year's event has already contributed to a severe food crisis across Central America's Dry Corridor, a strip of farmland running through Guatemala, Honduras, El Salvador and Nicaragua where smallholder farmers depend on predictable rains.

Rich countries are bracing too. The UK Met Office said on September 8 that Britain faces an autumn more likely to be wetter than average, with the chance of a warm, wet autumn around one and a half to two times higher than normal — and said El Niño was already at near-record levels. Met Office chief meteorologist Ian Lisk said the forecast was consistent with the historical influence of El Niño events, while cautioning that El Niño is only one of several climate drivers shaping the country's weather.

The WMO itself cautioned against treating the event's strength as a direct measure of local severity. The force of the Pacific signal does not automatically decide how hard any single country or region will be hit, the agency said, because local geography, the season and other climate factors shape what actually arrives on the ground.

Up to 50 million people could be affected

The human scale of the threat sharpened on September 17, when the inter-agency Global ENSO Analysis Cell published its humanitarian outlook on ReliefWeb. The report, which draws on UN agencies and humanitarian organizations, cites World Food Programme estimates suggesting that up to 50 million people globally could be affected over the next six to nine months. The same analysis stresses that the emerging risks must be understood alongside conflict, displacement, high food insecurity and high food prices, malnutrition, disease outbreaks, economic pressures and overstretched essential services.

Conditions have not improved since the group's June update, the report said. In many places, repeated shocks have already depleted household assets, increased debt and weakened the coping mechanisms people would normally rely on when drought, floods or price spikes damage their livelihoods. The warning lands hardest on communities already living with crisis: a flood or a failed harvest does not arrive in a vacuum where families have savings, functioning clinics and reliable safety nets.

UN Secretary-General António Guterres has warned that El Niño is being "supersized," describing a planet in "uncharted waters" and a "danger zone of extreme weather," and saying the race now is between rising risks and the world's commitment to protect people. Saulo has said the WMO launched the largest mobilization in the organization's 50-year history, working with national meteorological and hydrological services — the agencies on the frontline of delivering the forecasts that save lives and livelihoods.

Why this one looks different

What sets the 2026 event apart is the sheer amount of heat in the ocean. The tropical Pacific has been absorbing excess energy from years of record global warmth, and that stored heat is now feeding the El Niño cycle from below. El Niño also tends to push global average temperatures higher by releasing ocean heat into the atmosphere — scientists typically attribute an extra bump of roughly 0.1 to 0.2 degrees Celsius to El Niño conditions, though the exact figure varies event to event. Against the backdrop of long-term human-caused warming, that bump is why forecasters expect 2026 to rank among the hottest years observed, with some projecting 2027 could run even hotter as the full atmospheric effect develops.

Across the Atlantic, NOAA's Climate Prediction Center on September 10 put the chance of a very strong event during the Northern Hemisphere fall and winter at greater than 90 percent, and raised the odds of a historic-strength October-to-December episode to 75 percent, up from 69 percent in its August update. By the center's definition, historic strength means a three-month Relative Oceanic Niño Index value of at least 2.5°C — exceeding every El Niño in its record dating back to 1950. The center said the main Niño-3.4 yardstick stood at 1.8°C above average in August, while subsurface temperature anomalies topped 10°C above average at depth.

A separate line of research published in Earth's Future on September 3 helps explain why the consequences feel more extreme than a generation ago. According to the American Geophysical Union, bursts of extreme rainfall occur 66 percent to 315 percent more often after hot droughts than after cooler droughts. Looking at weather data from 1979 to 2023, the researchers found that every hot drought carries about a 45 percent chance of damaging wet conditions following it — and when the whiplash comes, the rain starts 10 percent sooner, falls 14 percent heavier and lasts 12 percent longer than rain after a cooler drought. The study projects that future greenhouse warming will make this drought-to-downpour whiplash more common, straining infrastructure, agriculture and ecosystems alike.

Preparation, the WMO says, is the point of the warning. The agency has stepped up preparedness and early-warning efforts, and national weather services are coordinating across borders — because once the rains or the drought arrive, the forecasts are only as useful as the plans made while the sky was still clear. For tens of millions of people in the path of the strongest Pacific heat pulse in decades, those plans are now being drawn up on a clock that runs out early next year.

Source: World Meteorological Organization. Additional reporting via ReliefWeb and the American Geophysical Union and the NOAA Climate Prediction Center.