More than 450,000 people could die from the extra heat caused by the super El Niño over the next six months, according to climate scientists’ estimates. This is on top of deaths already caused by rising temperatures from the climate crisis. The impact will be felt worldwide, from Indonesia to India, and Nigeria to the US. Many more deaths are expected from the droughts, wildfires, and flooding that El Niños bring.
The heat deaths have been estimated by region, and researchers say these projections show where protective measures could be introduced to save lives. Such measures could include better heat forecasts, cooling centres where people can take shelter, more staff at medical facilities during the hottest periods, and protections for outdoor workers.
A graphic showing the top 10 countries affected by El Niño-related heat deaths.
The El Niño currently heating the planet broke the highest temperature ever recorded for the phenomenon on Monday, several months before its expected peak. The heat is so much greater than in previous events that scientists have called it “mind-blowing” and “Godzilla-level.” El Niños are natural climate events but may be made worse by global heating.
“The estimate of 451,000 people is such a large number that it can be numbing, but it is made up of parents and children, grandparents and neighbours, people going to work, caring for families, and living their lives,” said Prof Michael Greenstone, co-founder of the Climate Impact Lab and at the University of Chicago, who co-authored the report.
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The death estimate covers the period from September to February 2027, which is when current temperature forecasts end. But higher levels of heat deaths are expected to continue until June or July 2027.
The countries most affected in the next six months are the tropical nations of Nigeria, Indonesia, Sudan, India, and Brazil. The US is in the top 20 most affected nations, with 3,500 projected additional heat deaths. More broadly, the Sahel region in Africa and south-east Asia are heavily affected.
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Flooding in Benitu, South Sudan, 2023: the report estimates 5,600 deaths in South Sudan from the additional heat brought by the super El Niño in the next six months. Photograph: Luke Dray/Getty Images
The El Niño is also a “postcard from our future,” the researchers said, pushing temperatures up to the level the climate crisis is projected to deliver in 20 years’ time.
“Increasing emergency response and better targeting our efforts can save many lives this year,” said report co-author Dr Tamma Carleton at the University of California, Berkeley. “But 20 years from now, once today’s extreme temperatures become the new normal, we don’t want to be in a constant state of emergency. We need to mobilise now to design, deploy and evaluate the tools that will save lives in the years ahead.”
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The projections were made using peer-reviewed methods that track the month-by-month relationship between temperature and additional heat deaths in 24,378 regions across the world. This was combined with forecasts for higher temperatures due to El Niño in the months ahead. The baseline was the number of heat deaths in the average month from 1996 to 2025.
Graphic
“People have been able to forecast when there’s going to be shocks to crops, and give advance warning of that,” said Greenstone. “This new report is opening the door to being able to do it for an even more important outcome – I would“The most important outcome is death,” he said. The report will be submitted to a peer-reviewed journal, but Greenstone said that given the urgency of the situation, “it would have been irresponsible to sit on it.”
Food supplies will also be affected by El Niño. In August, the World Food Programme warned that its effects could push about 50 million people into acute hunger and drive up prices. A major El Niño in 1877–1878 led to more than 50 million deaths from drought and famine, with India, Brazil, and China severely affected.
Professor Friederike Otto of Imperial College London told the Guardian on Monday: “The current El Niño event is a huge redistribution of energy in the climate system and is dangerous, because it is unfolding on top of a much warmer, human-influenced climate system.
“So in many places around the world, we will see never-before-experienced heat extremes, with all their consequences for health, food security, and water stress. El Niño comes and goes, but as long as we continue to burn fossil fuels, it occurs on an increasingly hotter baseline, making it much more difficult for communities to deal with the consequences.”
The Guardian’s climate forum 2026: On Tuesday 20 October, join Damian Carrington and our panel of experts—including Professor Andy Haines, Katie White MP, Asad Rehman, Shruti Suresh, Gareth Thomas, and Amy Fairman—for a hopeful, solutions-focused evening. Book tickets here or at guardian.live.
Frequently Asked Questions
Here is a list of frequently asked questions about the forecast that a massive El Niño could cause 450000 deaths over the next six months
1 What is El Niño in simple terms
El Niño is a climate pattern where the Pacific Ocean near the equator gets unusually warm This shifts weather around the world causing floods droughts heat and storms in different regions
2 Where does the 450000 deaths figure come from
It comes from research and risk models that estimate how many people could die from hunger disease and disasters linked to a very strong El Niño It is a projection not a confirmed count
3 Is this number certain to happen
No It is an estimate based on past El Niño events and current conditions The actual number depends on how strong the El Niño becomes and how well governments and aid groups respond
4 Why would El Niño cause so many deaths
El Niño can trigger droughts that ruin crops floods that spread disease and heat waves that harm health These effects can lead to food shortages malnutrition and illness especially in vulnerable regions
5 Which countries are most at risk
Regions already facing poverty and weak health systems are most at risk These often include parts of East and Southern Africa the Sahel Central America and South and Southeast Asia
6 How does El Niño actually lead to death
It usually works indirectly Crops fail water becomes unsafe and diseases like cholera and malaria spread People may die from malnutrition dehydration or preventable infections
7 What is the difference between El Niño and La Niña
El Niño is the warm phase of the Pacific pattern La Niña is the cool phase Both change global weather but in different ways and often in different regions
8 How often does a massive El Niño happen
Strong El Niño events occur roughly every 10 to 20 years The strongest ones like 199798 and 201516 caused major global impacts
9 What makes this El Niño massive
It means ocean temperatures are much warmer than normal over a large area That can make weather extremes stronger and more widespread
10 Can we prevent these deaths
We cannot stop El Niño but we can reduce deaths Early warning systems food aid clean water vaccination and droughtresistant crops
