The Next Heat Crisis Is Already Building in the Pacific Ocean

Outdoor women workers from the agriculture sector, India. Credit: Photo by Dibakar Roy, Pexel.

A major warming event called El Niño is likely building in the Pacific Ocean, according to forecasts from leading agencies including NOAA and ECMWF. Combined with a world that’s already getting hotter, this is projected to push deadly heat conditions into regions that have never experienced them before with impacts peaking as late as 2027.  

El Niño refers to a periodic event in the tropical Pacific when ocean surface temperatures rise by at least 0.5°C above average. This is part of a natural climate cycle known as the El Niño-Southern Oscillation (ENSO), which swings between warmer and cooler Pacific conditions every few years. El Niño events also release large amounts of heat from the ocean into the atmosphere, temporarily raising global temperatures.  

According to current forecasts, there is a ~62% probability of El Niño developing by mid-2026, with some suggesting it could intensify into a strong or even “super” event. 

A Super El Niño is where warming exceeds 2°C, four times the standard threshold, and the equivalent of a high body temperature tipping into a dangerous fever. This leads to more intense and widespread climate impacts when compared to a standard El Niño.  

At the same time, new scientific evidence shows that recent heatwaves (2003-2024) have already crossed the limits that humans can survive, showing clearly how natural climate variability when paired with long-term warming are amplifying global risks. 

A super El Niño could then act as a risk multiplier, increasing the frequency, intensity, and geographic spread of such life-threatening heat conditions. 

Key Highlights 

• Sea surface temperatures in the tropical Pacific may go up by 2°C above average, meeting the threshold for a Super El Niño (vs. 0.5°C increase for a standard El Niño)  

• Large volumes of subsurface warm water are moving east, an early and strong indicator of El Niño formation in 2026  

• Climate models suggest this could be one of the strongest El Niño events on record, with peak impacts expected during winter 2026–2027  

• A new study analyzing 6 major heatwaves (2003–2024) found all included periods of “non-survivable” heat for people over 65  

• Heat can affect people even below the previously thought 35°C wet-bulb limit. Wet-bulb temperature measures heat combined with humidity – the two together determine whether the body can cool itself by sweating

• In multiple events (e.g., 2015 Pakistan, 2023 U.S., 2024 Middle East), heat was non-survivable even in the shade  

• The study estimates that hundreds of millions of people are already at serious risk from combined heat and humidity 

Climate Change Link and Polar Connection 

Climate change doesn’t affect one thing at a time. It shifts ocean temperatures, atmospheric patterns, and polar ice all at once – and these changes interact.  

Long‑term warming of the global ocean and atmosphere, driven by rising greenhouse gas concentrations, affects background conditions in the Pacific that favour more intense or extreme El Niño events. Several studies find that human-caused warming has already increased the frequency of strong or extreme El Niño conditions compared with earlier decades, even when accounting for natural variability. 

Polar changes can influence the global climate, and the tropical Pacific feels those consequences. As Arctic sea ice melts and ocean-air interactions change, studies suggest this can amplify Pacific temperature swings (rapid rises and falls in ocean surface temperatures), making strong El Niño events more likely. 

In simpler terms, global warming, including accelerated warming in polar regions, appears to be modifying the “background climate conditions” against which El Niño develops, making the climate system more prone to extreme events. This does not mean the polar regions directly cause a Super El Niño, but that large‑scale warming and associated feedbacks across the global ocean–atmosphere system can amplify ENSO variability, creating conditions that favour stronger events. 

Where You Live and How it Affects You  

North America:  

• Western and southern U.S. will face increased storms and flooding during winter 2026–2027.  

• Southwestern U.S. faces higher risk of deadly heatwaves for older adults.  

• In March 2026, cities across the southwestern United States, including Phoenix, experienced extreme heat with several consecutive days near 41.1 °C. Scientists say such conditions would have been impossible without human-caused climate change, as more than 7,000 daily high-temperature records were broken and many locations saw their hottest March on record. 

South America:  

• Amazon and northern regions will face more drought risk and heat stress. 

• Southeastern and South Americans will face a higher likelihood of flooding because of El Niño rainfall patterns. 

• In February 2026, heavy rains in southern Peru triggered deadly flooding, affecting about 5,500 homes and forcing thousands to evacuate. 

• In early 2026, extreme heat and widespread wildfires affected southern regions of South America, including Argentina and Chile, where temperatures in some areas approached 50 °C, leading to severe fire outbreaks and significant heat-related impacts. 

Africa:  

• Eastern Africans face higher flood risk.  

• Southern Africa faces drought, compounded by extreme heat, creating potential non-survivable conditions in some areas.  

• The South African Weather Service reported that several stations in the Western and Northern Cape broke long-standing March temperature records, with Alexander Bay reaching 44.8 °C, Garies 43.5 °C, and parts of Cape Town close to 40 °C. 

Asia:  

• South Asia faces severe drought and life-threatening heatwaves, in urban and densely populated areas. 

• In India and Pakistan, pre-monsoon temperatures regularly rise above 50°C, and heat-related mortality in the region today exceeds 200,000 deaths per year. 

• Southeast Asia (Eg. Bangkok, Thailand) and Middle East (Mecca, Saudi Arabia) both face heat extremes approaching or exceeding human survivability limits. 

• In March 2026, northern Malaysia experienced a heatwave with temperatures approaching 40 °C across several districts amid persistent hot and dry conditions. 

Pacific Regions:

• In January 2026, a severe heatwave in inland southeastern Australia drove temperatures near 50 °C, with extreme heat and fire danger comparable to the 2019-20 Black Summer.

• New Zealand is experiencing a rapid increase in extreme heat events, with recent data indicating that such occurrences are happening four to five times more frequently than would be expected without long-term warming.   

• The region faces widespread drought and elevated wildfire risk.  

• The region also faces higher probability of non-survivable heat events in northern and interior regions.  

Worldwide:  

• Record high global temperatures in 2026–2027 caused by a Strong El Niño. 

• Vulnerable populations (elderly, outdoor workers, urban residents) face increased risk of heat-related chronic diseases and mortality.  

• Agriculture, fisheries, and ecosystems stressed by simultaneous droughts, floods, and extreme heat. 

What is Needed Now 

• Strengthen early warning systems (this year onwards) for heatwaves and El Niño-related extremes.  

• Protect vulnerable populations by providing information on health risks resulting from extreme heat and how they can be mitigated. Particularly vulnerable populations include older adults, pregnant women and children below 5 years of age and outdoor workers. 

• Integrate 2026–2027 climate forecasts into planning for water, agriculture, and public health.  

• Invest in heat-resilient infrastructure such as urban greening.  

• Help health systems be more prepared for heat-related chronic diseases and mortality.  

• Reduce emissions faster this decade to limit compounding climate risks.  

• Support research and monitoring of human heat thresholds and regional exposure. 

Read more about extreme weather here. 

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