A Wind Chill Advisory has been issued for all of northern Illinois and southern Wisconsin beginning late Thursday evening, lasting through mid-morning Friday. Temperatures have fallen very quickly behind a cold front Thursday, with current readings down into the teens as of 3pm and wind chills below zero.
Incoming high pressure from the northwest will allow winds to become light late in the evening and overnight. As a result, temperatures will fall quickly under mainly clear skies. Overnight lows will range from -5 to -10 degrees, with wind chills as low as -25 degrees in some locations. Frostbite can occur on exposed skin in as little as 30 minutes. We’ll see plenty of sunshine throughout the day Friday with wind chills gradually warming to around 0 degrees by the afternoon.