Polar Vortex Is Strengthening: What It Means For IL Winter Temps, Snow

The forecast for warm temperatures on Christmas Day in Illinois is a harbinger of what’s to come for most of the country through March, according to a new winter forecast.

Nothing is more magical than a white Christmas, but in Illinois, The Weather Channel said it is not expecting a chance of one happening due to warmer weather. A high of 45 degrees is forecast on Christmas Eve, which will then climb to 54 degrees on Christmas Day.

Instead of being blanketed on Christmas, the Chicagoland area experienced the snowiest November day ever recorded — plus multiple days of below-zero wind chill — after Thanksgiving, Patch reported. Interestingly, O'Hare Airport in Chicago has seen almost as much snow so far this winter as it did all of last season, according to the National Weather Service.

RELATED: Snowiest November Day Ever Recorded Cancels Flights, Causes Crashes

After a cold start to the winter, temperatures are expected to climb into the early part of 2026 in the South and East as the stratospheric polar vortex strengthens at the beginning of the year, according to The Weather Channel’s outlook.

It may sound counterintuitive, but the stronger a polar vortex is, the less impactful it is, according to The Weather Channel. A stratospheric polar vortex, which is higher up in the atmosphere and usually stable, differs from the better-known tropospheric polar vortex, which is lower down in the atmosphere and typically brings severe cold snaps to mid-latitude states.

The ongoing flip to cooler, wetter weather in the North and Northwest is also likely to continue, the forecast said. Bouts of wetter, colder weather in other parts of the country aren’t out of the question.

The private weather service’s January to March outlook for Illinois calls for:

• January: Above-average temperatures
• February: About average temperatures
• March: Slightly above-average temperatures

Highlights of The Weather Channel’s outlook include:

• January will likely continue the late-December pattern with above-average warmth across the southern two-thirds of the country.
• February could see the warmest weather relative to average along the East Coast.
• Without the polar vortex in play, conditions are expected to resemble La Niña: warmer than average in the south and cooler in the north.
• The northern U.S. will likely see wetter-than-average conditions, while the southern U.S. is more likely to be drier.