The unrelenting wintry grip on the region is expected to continue for the foreseeable future.
Forecasts show the next major change coming Thursday, when temperatures could reach a high around 30 degrees.
In the meantime, residents should brace for snow, bitter cold and wind gusts that will push the powder across roads, driveways and sidewalks.
Indiana State Police reported several slide-offs Saturday on Interstate 65, north of Crown Point, because people were driving too fast for conditions.
Lake, Porter, Newton and Jasper counties in Indiana and Cook and Will counties in Illinois fall under a winter storm warning and wind chill warning until midnight Sunday.
The winter storm warning means the area could experience significant snowfall and strong winds, making travel hazardous or impossible.
The wind chill warning means the wind will combine with very cold air to create dangerously low wind chills that could lead to frostbite, hypothermia or death if precautions are not taken.
Snow may be heavy during the day Sunday, with total accumulation between 4 and 8 inches. Temperature highs are expected in the mid-20s. Wind gusts could reach 35 mph, according to the National Weather Service.
Sunday night is expected to bring high winds, blowing snow and the start of bitter cold, with temperatures dipping as low as 17 degrees below zero. The lowest wind chill readings will come after midnight, with some dropping to 40 degrees below zero and wind gusts up to 40 mph, the National Weather Service predicted.
Monday will be even colder and almost as windy.
Record-breaking cold temperatures are likely, with highs between 8 and 12 degrees below zero. The wind chill could make it feel between 35 and 45 degrees below zero, with wind gusts up to 30 mph, according to the National Weather Service.
Monday night will bring lows between 12 and 16 degrees below zero and wind chills between 30 and 40 degrees below zero.
The bitter cold could lead to school and business closures.
Valparaiso University on Saturday tweeted a message that its operations will be suspended from Sunday until noon Tuesday because of the weather.
Check www.nwi.com for a full list of warming shelters and updated school closing information.