The bitter cold temperatures are expected to return Monday morning.
A wind chill advisory has been issued for Kane County from midnight through 9 a.m. Monday. A wind chill advisory has also been issued for McHenry, Lake and Kendall counties.
Wind chill readings of 15 to 25 below zero are expected Monday morning for counties throughout northern Illinois. A wind chill advisory means wind will combine with cold air to generate low wind chills that could result in frost bite or hypothermia.
Those who must go outdoors are reminded to wear a hat and gloves.
The National Weather Service is also predicting river flooding along portions of the Illinois and Kankakee rivers and there is an increased risk of localized flooding, according to the National Weather Service.