A potentially historic El Niño is already forming in the tropical Pacific, and it could be the strongest in recorded history. The timing is not subtle. Forecasts point to a very strong event during the Northern Hemisphere fall and winter, with sea surface temperatures in key Pacific regions already running well above normal.
What the new study says
A study published in Science in late August 2026 reports that El Niño events over the past 40 years are nearly 40% stronger than in the pre‑industrial era. The authors built a 1,000‑year record from modern and ancient corals in the Galápagos Islands and found that recent El Niños exceed anything seen in the millennium before about 1850. Lead author Julia Cole, of the University of Michigan, said the big El Niño events of the last 40 years are not normal in that long context.
The research does not claim to prove every detail of cause and effect. It does show that the strength of El Niño changes in parallel with the warming of global temperature. The team also ran climate models that included volcanic eruptions and solar variability over the last 1,000 years. The recent rise in El Niño intensity still stood out.
Why this story now. A new scientific paper lands just as forecasters say there is more than a 90% chance of a very strong El Niño this fall and winter. That is convenient timing for attention. It is also the moment when decisions about water, crops, insurance, and emergency planning start to harden. Who benefits from framing this as a once‑in‑a‑millennium shock. Governments that want urgency without admitting long‑term planning gaps. Insurers that need a clean narrative for rate changes. Climate advocates who have been asking for exactly this kind of headline. None of that makes the science wrong. It does make the packaging worth watching.
What could happen next
Across the Southern Tier of the United States, forecasters are monitoring a southward shift in the Pacific jet stream that could bring an early autumn rainy season. Enhanced monsoon and tropical moisture may increase rainfall from California and the Desert Southwest through the Southern Great Plains and Gulf Coast. That would be welcome in drought‑stricken areas. It also raises the risk of flooding and mudslides in elevated terrain.
Areas from North Carolina into central Florida are expected to be wetter than average. Because the primary storm track would sit farther south, severe storm chances across the Gulf Coast and Southeast would increase. In the Pacific, warm water fuels more storm generation. The Eastern Pacific season has already logged nine named storms ahead of peak season, including a Category 5 hurricane in late July. In the Atlantic, El Niño tends to shear the tops off developing storms, which can mean fewer hurricanes there.
Winter patterns could tilt warmer across much of Canada and the northern U.S., with British Columbia’s south coast potentially seeing less precipitation and a lower snowpack. The southern U.S. is likely to experience a much wetter winter. In the tropics, El Niño can suppress rainfall in parts of the western Pacific, Central America, and tropical South America, while raising drought risk in southern Africa and northeast Australia. Large El Niños also release more heat from the ocean to the atmosphere, which can lift global average temperature, especially in the calendar year after the winter peak.
What would this story look like if the opposite were true. If the coral record had shown no long‑term strengthening, the same forecasts would still drive headlines about a big El Niño this year. The difference would be in the subtext. Without the 1,000‑year frame, the focus would sit on seasonal variability and preparedness, not on a march toward unprecedented extremes. The policy asks would change. So would the pressure on leaders to tie this event to emissions targets.
There is also the matter of what the study does not cover. Coral records capture temperature swings tied to El Niño in the eastern Pacific. They do not measure every impact on every region. They do not settle how much of the change is natural variability versus human forcing. The authors are careful on that point. The public messaging around the paper is less careful. That gap is where anxiety grows faster than understanding.
For people living along the Gulf Coast or in the Desert Southwest, the practical question is simple. Will the rain come too fast, or not fast enough. For farmers in the western Pacific and tropical South America, the question is whether dry spells will tip into crop failure. For insurers and reinsurers, the question is how to price risk when the baseline itself appears to be moving. For politicians, the question is whether to treat this as a weather story or a climate story. Both answers carry costs.
The strongest El Niños in the last 1,000 years are happening now, according to this work. A potentially historic El Niño is already forming. That is the fact set. The rest is about who gets to define the emergency, and who pays for it.