Northeast Missouri and western Illinois enter the wintertime deep freeze Tuesday night and Wednesday.

The National Weather Service has issued a Wind Chill Advisory for Knox, Lewis, Marion and Shelby counties in Missouri and Adams and Brown counties in Illinois.

Forecasters expect very cold air and strong winds to combine for wind chills as low as 15 below zero overnight Tuesday and Wednesday morning.

Weather Service officials say that if you must venture outdoors, make sure you wear a hat and gloves, making sure all exposed skin is covered.

High temperatures are not expected to top the freezing mark again until after the new year.