Sunday's snowfall caused 21 crashes on Interstate 80/94 and Interstate 65, Indiana State Police said.
Troopers said most of the accidents were caused by cars sliding off the road. There weren't any major injuries reported in any of the crashes.
The crashes caused delays on the roads and state police temporarily closed an eastbound lane of I-80/94 near the Cline Avenue exit.
Indiana State Police said they had 6 crashes about 10:30 p.m. Most of the crashes were on I-80/94 between the Broadway and Ripley Street exits. Two motorists slide off the road on the northbound lanes of I-65 near the Crown Point exits.
The National Weather Service issued a hazardous weather outlook for Lake County, Porter County, Jasper County and Newton County. Snow was expected to continue falling overnight with freezing drizzle and sleet. The wind chill is expected to dip to 15 degrees below zero Monday night.
A freezing rain advisory was issued Sunday until midnight for Newton County and Jasper County.
According to the National Weather Service, 1.4 inches of snow had accumulated at O'Hare International Airport by Sunday afternoon. There weren't any snow totals for Northwest Indiana.