Early-Onset El Niño. (New York Times)
El Niño is the planetâs naturally recurring chaos agent, scrambling weather patterns, spiking global temperatures and typically reaching full strength by December.
But this yearâs El Niño, which is expected to be record-breaking, is already strong and having big effects, nudging up global temperatures and causing dry spells and crop failures on multiple continents.
These on-the-ground consequences reflect the magnitude of the changes in the Pacific Ocean, where El Niños develop when unusually warm waters build up. These episodes occur every two to seven years and have contributed to planetary swings going back millenniums. But this yearâs is on track to be the strongest in nearly 80 years of records.
Scientists are debating whether human-caused climate change is tilting the odds toward stronger and more frequent El Niño events. The El Niños of the past few decades have been comparably strong. But the variables that combine to create an El Niño are complex, and some experts argue the recent trend could just be a random signal.
Whatâs clear is that El Niñoâs gyrations are adding to the stronger storms, drier dry spells and fiercer wildfires that global warming is already bringing about. El Niño will magnify those phenomena in some regions and could lift global temperatures to record levels next year, as the heat from the Pacific spreads around the world.
âWhat weâll see in 2027 is a sneak peek of what the new normal will be in 2035,â said Zeke Hausfather, a climate scientist at Berkeley Earth, a nonprofit research organization. âWeâll see things that have never happened before in our history in terms of temperature, drought conditions, extreme heat.â
El Niño events are measured by looking at sea surface temperatures in a specific rectangular zone of the Pacific Ocean. Temperatures there have soared over the past three months, and forecasts suggest that, by yearâs end, they could exceed normal levels by more than they did during the strongest El Niños in modern history, which occurred in 1982-83, 1997-98 and 2015-16.
Between October and December, the National Oceanic and Atmospheric Administration says thereâs an 81 percent chance that El Niño conditions will be âvery strong,â meaning the three-month average temperature in that zone of the Pacific is 2 degrees Celsius, or 3.6 degrees Fahrenheit, higher than normal. But forecasts show that daily ocean temperatures during that period could spike to more than 3 degrees Celsius above normal.
âMaybe it doesnât sound that big: three or even four degrees. We see that temperature variation over the course of a day,â said Samantha Stevenson-Karl, an associate professor and climate modeler at the University of California, Santa Barbara. âBut the ocean doesnât change that much. Like, ever.â
The extra heat in the waters of the Pacific affects air temperatures, too. For the first months of the year, 2026 was clearly cooler than 2024, the planetâs hottest year on record. But Dr. Hausfather still gives 2026 a 40 percent chance of being Earthâs warmest year on the books, a sign of how the pendulum could be swinging. According to NOAA, last month tied July 2024 as the worldâs warmest July since global record-keeping began in 1850.