Bitter cold to descend on northern Illinois, last most of the week

Bitter cold is set to come to northern Illinois by Sunday evening, bringing subzero wind chills, and is expected to linger for most of the week.

Saturday evening until 8 to 10 p.m. parts of McHenry and Lake Counties could see freezing drizzle, National Weather Service meteorologist Lee Carlaw said.

There aren’t expected to be any significant impacts from the drizzle but it could create slick spots on untreated surfaces, Carlaw said.

Very late Saturday and through Sunday morning, areas close to Lake Michigan could experience lake effect snow; chances go up closer to the lake, Carlaw said.

Cold air arrives to the region Sunday afternoon. The wind chill Monday morning is expected to be minus 20, Carlaw said. A wind chill that cold is the threshold for a wind chill advisory, and a wind chill of minus 30 triggers a warning.

While most schools will be closed Monday for Presidents Day, classes could be delayed or schools closed Tuesday because of wind chills.

Monday night into Tuesday could see wind chills of minus 20 to minus 25. Wind chills will remain near zero or below zero for the whole week, Carlaw said.

Frostbite is possible in about 30 minutes or less. People should limit time outdoors, cover all exposed skin and bring pets inside, according to the weather service.