Berkeley Earth said El Niño North America weather could face a strong jolt after the event officially formed in June, with a 90% chance that tropical Pacific temperatures will push beyond anything recorded in about 150 years of observations. The strongest effects are expected to reach the United States in the fall and peak during the winter.
Berkeley Earth and June
The July 23 analysis gave the forecast its sharpest number: a 90% chance of temperatures in the tropical Pacific exceeding the modern record span. That is the part readers in the United States should watch first, because the event is already in place and its most significant weather effects usually lag the ocean signal by months.
Berkeley Earth’s warning also matters because El Niño can reshape seasonal patterns across North America, not just the tropical Pacific. A strong event is associated with wetter conditions in the South, milder temperatures in the North, and a quieter Atlantic hurricane season, but each El Niño differs in its evolution, spatial pattern and impacts.
Michelle L'Heureux on the South
Michelle L'Heureux, a physical scientist at NOAA's Climate Prediction Center, said, "El Niño tends to increase the storm track over the southern tier of the United States, increasing the chances of above-average precipitation." She said northern parts of the country could see warmer temperatures while other regions may experience drier conditions.
That southward shift can leave parts of the northern United States drier than normal and raises the likelihood of above-average temperatures there. The same pattern can also send more thunderstorm activity across the Gulf Coast and in the lower Mississippi and Tennessee valleys, while spring and summer wildfire risk tends to decrease across the Southeast and parts of the Southwest.
World Meteorological Organization
A strong or very strong El Niño typically strengthens the subtropical jet stream during the fall and winter, steering more storms across the southern United States. That can mean wetter-than-normal conditions across parts of the Southwest, including the Great Basin and southern Rockies, while western and central Canada often sees milder conditions and below-normal snowfall.
The pattern is not one-directional. Parts of the Rockies can receive above-normal snowfall, the Northern Rockies can face higher spring wildfire risk if the northern United States turns warmer and drier, and the Ohio and Tennessee valleys often run drier than average in winter. The risk of powerful coastal storms, including nor'easters, can still be elevated during a strong El Niño.
Steven DiMartino, chair of the American Meteorological Society's Board of Digital Meteorologists, said, "While you only need one hurricane to have significant impacts, a very strong El Niño produces significant wind shear in the tropical Atlantic." He said that wind shear prevents most tropical waves from forming.
The World Meteorological Organization expects El Niño to persist well into late 2026. For readers across the United States, the practical takeaway is that the main shift does not arrive all at once: fall is when the first sizable changes should start, winter is when they should peak, and the Atlantic hurricane season can still be muted even as the southern tier of the United States stays on a stormier track.
