La Niña Watch Issued: What It Could Mean For Wisconsin's Winter

WISCONSIN — With summer winding down, attention is turning to what kind of winter may be ahead.

The National Oceanic and Atmospheric Administration (NOAA) has issued a La Niña Watch for the 2025–26 season, meaning there is about a 55 percent chance a weak La Niña will develop this fall and early winter before conditions return to neutral.

La Niña occurs when the central and eastern Pacific Ocean cools more than usual. It typically causes the northern United States, including Wisconsin, to be colder and wetter than normal, while the southern states turn warmer and drier.

El Niño, by contrast, usually brings the reverse: warmer weather in the north, wetter weather in the south, and sometimes large, unpredictable storms.

"ENSO-neutral is most likely through the late Northern Hemisphere summer 2025 (56 percent chance in August–October)," NOAA said. "Thereafter, a brief period of La Niña conditions is favored in the fall and early winter 2025–26 before reverting to ENSO-neutral."

In other words, NOAA says the Pacific Ocean will likely stay neutral through late summer. After that, there’s a fair chance of a short-lived, weak La Niña in the fall and early winter before conditions return to neutral.

But for now, NOAA’s maps show no clear signal on whether Wisconsin will see above- or below-average temperatures or precipitation this winter.

Nationwide

Much of the southern U.S., stretching from California’s Central Coast to Florida and up the entire East Coast, is moderately likely to see above-average temperatures this winter. For much of the Midwest, it is equally likely to be above or below normal. Just Washington state and southeast Alaska are likely to see below-average temperatures.

Much of the southern U.S., stretching from the Bay Area in a U-shape to the Washington D.C. area, is moderately likely to see below-average precipitation. Pockets of the Midwest and parts east, including Indiana, Ohio, and Kentucky, and much of Montana, Wyoming, and Alaska, are 33-40% likely to see above-average precipitation. The rest of the country remains uncertain.

On that note, much of this forecast remains relatively uncertain. "Nothing is guaranteed in this business," said Michelle L’Heureux, scientist at the National Weather Service’s Climate Prediction Center.

NOAA updates its long-range outlooks monthly, and the next forecast is scheduled for Sept. 19.

Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center website. See here for predictions through November 2026.