People navigate snow-covered sidewalks in the Humboldt Park neighbourhood n Chicago, Illinois. Scott Olson / AFP

Much of the snow that was supposed to fall in the Midwest has come down and now it's time for the main event: Record-breaking cold.

The National Weather Service said on Tuesday and on Wednesday may see record cold from the southern Plains to the Mississippi Valley to the Great Lakes and beyond, thanks to what it calls an "arctic airmass" that started in Siberia and has been spilling over a big chunk of the Midwest and East Coast.

There will still be plenty of snow into Tuesday in parts of the Northeast as the weather service reported the region may see up to 30.5 centimetres of snow, creating what it called "hazardous travel conditions."

Between 2 and 6 inches of snow fell in northern Illinois, forcing the cancellation of about 2,200 flights at Chicago's O'Hare International airport.

A woman clears off a Divvy bike in Chicago on Monday. Rich Hein / AP

The National Weather Service said Monday night that snowfall has ended in northern Illinois, but lake effect snow will persist in northern Indiana into early Tuesday.

In addition to flight cancellations, O'Hare was plagued by delays that averaged 80 minutes. Midway International airport reports 94 flight cancellations and delays averaging 15 minutes.

Meanwhile, temperatures were forecast below freezing as far south as the Texas Gulf Coast.

Records are expected to be broken in Chicago, as well. Weather service meteorologist Kevin Birk said the high for the Windy City is expected to reach minus 6º Celsius, which is seven degrees lower than the previous record set for Nov.12.

Low temperatures in Illinois, Wisconsin and Iowa could drop into the single digits, according to Birk.

A resident walks through snow with her child in the Wicker Park neighbourhood in Chicago, Illinois, on Monday. Scott Olson / Agence France-Presse

In Minnesota, Monday was the coldest high temperature in three decades in the Twin Cities at -8º Celsius and some Minnesota lakes were freezing earlier than normal.

"This is an air mass that's more typical for the middle of January than mid-November," said Birk.

"It is pretty much about the coldest we can be this time of year (and) it could break records all over the region." In some areas, the mercury fell quickly. Temperatures in Denver climbed past 21º Celsius over the weekend only to fall to -10º Celsius early Monday.

As the weather made driving difficult in much of the Midwest, authorities said Monday's snowfall was to blame for four deaths.

The Eaton County Sheriff's Office in Michigan said two women, ages 81 and 64, and a 57-year-old man were killed in a two-vehicle crash caused by poor road conditions. And in Kansas, the Highway Patrol said an 8-year-old girl died in a three-vehicle wreck.

Agencies