Latest Chicago Winter Weather Outlook 2024-25 – NBC Chicago

Get ready for a wetter, snowier winter, Chicago — and a colder one too…maybe.

That's according to the National Oceanic Atmospheric Administration's latest winter weather outlook for 2024-25, which says a “La Niña” winter is expected, ultimately leading to a “wetter than normal” winter in the Great Lakes, particularly parts of Wisconsin, Illinois and Indiana.

According to Kevin Jeanes, the forecasts are a far cry from Chicago's winter of 2023-24 – an El Niño winter – which ended up being the fourth warmest winter on record.

Winter weather

The winter precipitation outlook for the Chicago area is expected to be above average, Jeanes said.

“That would be beneficial because we have been experiencing some sort of moderate drought,” Jeanes said. “We need that.”

According to the National Weather Service, 18.5 inches of snow was recorded during the 2023-24 meteorological winter, which was 11.1 inches below normal.

For 2024-25, the big question will be whether temperatures will cause precipitation to fall in the form of rain or snow

Is it getting colder?

It depends on.

That could be the case, Jeanes said, but that's only true compared to how warm temperatures will be in 2023-2024.

“It was so warm last winter,” Jeanes said. “If temperatures are closer to average, it will feel colder than last year.”

Jeanes said NOAA predicts “equal chances” that temperatures will be above or below average.

“I’m not sure it’s going to be a colder winter,” Jeanes said. “It has an equal chance of being above average or below average.”

However, a much colder winter is expected across the Northwest, Jeanes noted.

La Niña winter forecast for Chicago

According to NOAA, they have implemented a number of upgrades to forecast tools, including an experimental model called the Probabilistic Winter Storm Severity Index. That data was used to support this year's forecasts after they were first implemented in late 2023, officials said.

According to the University of Illinois, stronger La Niña patterns can result in winters that are typically “warmer and wetter than average,” with more snow and winter storms during these seasons. A La Niña also typically leads to cooler springs if the pattern continues.

During a La Niña event, trade winds are stronger than usual, pushing warm water away from the Americas and into Asia. This enables a process known as “upwelling,” which brings cold water to the ocean’s surface.

These cold waters then cause the Polar Jet Stream further north, leading to drought in the southern United States and increased rainfall in the Midwest and Pacific Northwest.

According to the latest updates from the Climate Prediction Center, La Niña preferentially occurs between September and November and is expected to last at least into the winter months.