Chicago's Streets and Sanitation Department says it has deployed 200 snow plows and salt spreaders, mostly on main roads.
Twenty-six smaller vehicles are working on side and residential streets.
The snow rolled in about noon, bringing 1 to 2 inches of snow to northeast Illinois, including Cook, Lake, Kane, and McHenry counties, according to National Weather Service meteorologist Ben Deubelbeiss.
Eyewitness News meteorologist Phil Schwarz said many areas to the southwest of Chicago saw up to five inches. He also said most of the snow would fall by 7 p.m. Saturday.
Saturday afternoon, the city of Chicago deployed 200 snow plows and salt spreaders, said Molly Poppe, the spokeswoman for the city's Department of Streets and Sanitation. The fleet focused on salting and removing snow on arterial roadways throughout the day, and planned to side and residential streets once the snow has stopped and main routes are clear.
Counties in northwest Indiana can expect about the same snowfall before the storm tails off about 9 p.m., Deubelbeiss said. Suburbs south of Interstate 80 and parts of Will County could see 3 to 5 inches by Saturday night
Sunday's high of 32 degrees should offer Chicago a brief respite from the severe winter weather, but temperatures are expected to plummet early next week.
Slight accumulations of snow may return Monday and Wednesday nights, with an arctic blast moving in Monday that will keep temperatures in the teens and single digits for most of the week, Deubelbeiss said.
Wind chills Monday night could bottom out at 20 degrees below zero, enough to bring about flashbacks of "Chi-beria" for many Chicagoans.
"We've had an active start to the weather year to say the least," Deubelbeiss said.
(The Sun-Times Media Wire contributed to this report.)