The National Weather Service issued a cold-weather advisory for Chicago and other parts of the state this weekend, warning of “dangerously cold wind chills” that could dip as low as 20 to 25 degrees below zero.

A piece of the polar vortex is spilling into the Midwest, creating extreme cold for the Chicago area and northwest Indiana for the next few days.

Monday, the temperature is expected to drop to minus 3 at O’Hare International Airport. A low of minus 7 is expected at O’Hare Tuesday.

Temperatures will drop into the single digits and negatives starting Saturday through early next week. Chicagoans should wear lots of layers and limit time outdoors.

The drop in temperatures in Chicago has raised concerns about river ice formation, which could lead to ice jams in major waterways.

Chicago faces cloudy skies and potential snow with risks of slick travel conditions and a plunge in temperatures by the weekend.

In Chicago, snow seasons are tracked from July through the following June. The area normally can expect 38.4 inches, according to the National Weather Service. Chicago was warmer than average during the 2023-24 season due to a La Niña climate system,

Monday and Tuesday will see cold temperatures around 18 to 19 degrees during the day, falling to single digits at night.

The dramatic drop in temperatures highlights a continuation of the Midwest's colder-than-usual start to the year. Tuesday's west winds, gusting up to 25 mph, are expected to exacerbate the chill factor,

Temperatures are expected to plunge into the single digits Saturday night and remain there until Wednesday. Wind chill temperatures are expected to reach as low as negative 14 degrees.

A Cold Weather Advisory is in effect for Chicago with wind chills as low as -25˚, increasing the risk of frostbite in 30 minutes. Warming centers are open throughout the city from Jan. 18 to Jan. 24,

Temperatures will plunge into the single digits by early Sunday, and likely won't rise above the single digits until Wednesday.