El Niño is now the strongest it has been in 1,000 years, according to new research from the University of Michigan, which reconstructed ocean surface temperatures over the last millennium by looking at fossilized corals in the Galápagos Islands.
The study, published in the journal Science, found a large recent increase in the variability of sea surface temperature in the eastern equatorial Pacific compared to previous existing paleorecords. That increase also parallels rising global temperature and results from stronger El Niño events.
“We’ve been seeing some very strong El Niño events in the late 20th and early 21st century, and what we didn’t know was how unusual those are,” said lead study author Julie Cole, environmental scientist at the University of Michigan.
“We found that, on average, El Niño events have been stronger in the past 40 years than at any time in the past millennium, with higher temperatures that lead to more powerful effects on weather,” Cole wrote in the Conversation.
She explained temperatures across the equatorial Pacific Ocean have warmed dramatically in 2026, signaling the onset of a strong and potentially historic El Niño—which could affect weather not just in the Pacific, but across the U.S. and around the world—as El Niño events become stronger and more destructive.
The results provide a long-term framework for understanding the Pacific El Niño–Southern Oscillation (ENSO) and how it is impacting ecosystems, infrastructure, and humans worldwide, the study said.
The National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center is also saying El Niño is strengthening, with a greater than 90% chance of a “very strong event” in the Northern Hemisphere during the 2026 hurricane season this fall or winter.
What is El Niño?
El Niño is a complex weather pattern, referring to the warming of the ocean surface, or above-average sea surface temperatures, in the Pacific Ocean.
Winds that normally blow from west to east weaken—and in some cases, they blow east—disrupting normal weather and creating more extreme meteorological events, per the U.S. Geological Survey (USGS). As the winds “take warm water from South America towards Asia,” that’s replaced by cold water that rises, known as “upwelling,” according to NOAA.
The results: intensifying storms and flooding here in the U.S., particularly in the Southeast and Gulf Coast, which can also create wildfires and drought. The 2015 Super El Niño caused a significant Caribbean drought.
