Scientists are warning that El Niño 2026 could become one of the strongest, if not the strongest, on record after a new analysis found a 90% chance that tropical Pacific temperatures will climb beyond anything measured in about 150 years of observations. El Niño officially formed in June, and the weather pattern is now building toward the period when its effects usually hit hardest.
That matters because the biggest changes for the U.S. are expected to show up in the fall and peak in winter, when the pattern can reshape rain, snow and storm tracks across North America. The World Meteorological Organization expects El Niño to persist well into late 2026, giving the event a long runway to influence weather on both sides of the border.
Michelle L'Heureux said El Niño tends to increase the storm track over the southern tier of the United States, which raises the odds of above-average precipitation there while leaving the north with a different outcome. In a strong El Niño, the southern shift in the storm track can make parts of the northern U.S. drier than normal even as other areas turn wetter and cooler than usual.
That split is one reason the pattern draws so much attention. A strong El Niño typically brings wetter and cooler-than-normal conditions from late fall through winter, with thunderstorm activity often increasing along the Gulf Coast and in the lower Mississippi and Tennessee valleys. It can also bring wetter-than-normal conditions across parts of the Southwest, including the Great Basin and southern Rockies, while spring and summer wildfire risk tends to decrease across the Southeast.
But the same setup does not help every place at once. The northern U.S. tends to be warmer and drier during a strong or very strong El Niño, winters are often drier than average across the Ohio and Tennessee valleys, and western and central Canada usually see milder conditions and below-normal snowfall even as parts of the Rockies can receive above-normal snowfall. Strong El Niño winters can also keep the risk of powerful coastal storms, including nor'easters, elevated.
El Niño is a natural climate pattern that can bring extreme weather to many parts of the world, and each event evolves a little differently. Even so, the broad mechanism is familiar: a strong or very strong El Niño typically strengthens the subtropical jet stream during the fall and winter, pushing the storm track south and helping suppress Atlantic hurricane activity. Steven DiMartino said that while one hurricane can still be enough to cause major damage, a very strong El Niño produces significant wind shear in the tropical Atlantic.
What happens next is less about whether El Niño will matter than how far it goes. The record-level forecast points to a winter with sharper regional contrasts, from wetter stretches across the South to warmer and drier conditions farther north, while the strength of the event will determine how much of the season is reshaped before it finally fades late in 2026.
