The Philippines, Vietnam, Thailand and Cambodia could together record about 19,400 more heat-related deaths than usual between September and February as an exceptionally strong El Niño drives temperatures higher, according to projections released on September 23, 2026, by a research group based at the University of Chicago.
The Southeast Asian estimate is part of a larger calculation by the Climate Impact Lab, which puts the possible number of excess heat deaths worldwide at as many as 451,000 from June 2026, when the phenomenon took hold, through the end of February 2027. To arrive at the figure, researchers compared the deaths expected under El Niño’s elevated temperatures with the deaths expected if temperatures stayed close to the average of the past 30 years.
Indonesia faces about 19,300 additional deaths on its own, while India is projected to see 15,800 and Brazil 13,300. The heaviest toll is expected in the Sahel, the semiarid band of countries along the southern edge of the Sahara, where the projection reaches roughly 66,800.
In the Philippines, the state weather bureau expects the event to reach “very strong” status in October and to keep gaining strength through the first half of 2027. Ana Liza Solis, chief of the Climate Monitoring and Prediction Section of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), called the current warming “unprecedented in terms of intensity.”
About 45 provinces had logged rainfall shortfalls since El Niño set in this year, based on PAGASA’s tally as of September 21. The agency forecasts “below normal” rainfall in Luzon, the Visayas and Caraga in October, with Northern Luzon and Southern Mindanao likely to see near-normal amounts. Rainfall is expected to fall to “way below normal” levels in November, followed by a “significant reduction” from December that could hold until the first quarter of 2027.
Fewer storms are also in the outlook. PAGASA expects only one or two tropical cyclones to enter or form inside the Philippine area of responsibility from October to December, no more than one in January 2027, and a slim chance of another in February and March.
“This situation needs to be taken seriously, particularly because of its potential impacts on rainfall and water resources,” PAGASA administrator Nathaniel Servando told reporters at a press conference. The agency pledged to support mitigation work in the most exposed sectors, including agriculture, water supply, energy and public health.
The country has gone through strong to very strong El Niño episodes before, in 1982 to 1983, 1997 to 1998 and 2015 to 2017.
Michael Greenstone, a co-founder of the Climate Impact Lab and co-author of the report, said the research shows the danger is greatest where high temperatures and poverty overlap. Richer communities, he explained, tend to have better access to air conditioning, dependable water and working health systems.
“If you’re already in a hot place, the extra couple of degrees are going to be much more dangerous,” Greenstone said.
He added that the threat will probably outlast the El Niño itself, which is expected to fade by February, and that its effects could linger well into the summer of 2027.
The study places most of the burden on developing nations, a group often referred to as the Global South, many of which are already contending with food insecurity and high energy prices linked in part to climate change and the fallout from the war in Iran.
Although El Niño is a naturally occurring pattern, this year’s event is unfolding on a planet already warmed by human activity. The lab estimates that global land temperatures could run about 1.2 degrees Celsius higher during this El Niño, bringing 44 percent more extremely hot days than a typical year, conditions the report says climate change could make routine roughly two decades from now.
Abhiyant Tiwari, a heat expert at NRDC India who did not take part in the research, said the projections should push governments to act rather than simply add to public alarm. India has carefully developed heat plans, he noted, but carrying them out and securing the money to fund them remain difficult.
“The real measure of our preparedness is not how many heat warnings we issue, but how effectively we protect people and reduce preventable deaths,” Tiwari said.
Among the steps the report recommends are heat-warning systems, cooling centers, hydration stations, safeguards for outdoor workers, added hospital capacity and targeted outreach to older people and other vulnerable groups.
The authors also urge governments to adopt anticipatory financing, which would allow funds and resources to be released before dangerous heat reaches its peak.
