CHICAGO (CBS) — With temperatures plunging below zero again overnight, Chicagoans were starting another work week in frigid conditions, and the city was approaching the record for number of days of subzero cold.

As Monday morning’s temperature dipped to 3 below zero at O’Hare International Airport, Chicago now has had 20 days of below zero temperatures this winter. Temperatures were even colder in the outlying suburbs, where it was up to 14 below in Aurora and McHenry, and 13 below in Kankakee.

Only six winters on record have had more days of below zero weather in Chicago: 1884-85, 1935-36, 1962-63, 1981-82, 1874-75, and 1978-79.

The record for most days of below zero temperatures was set in the winter of 1884-85, when there were 25 such days. With more than a month left until the first day of Spring, and at least one more day of subzero temperatures this week, it’s quite likely Chicago will break that record.

A wind chill advisory was in effect for the entire Chicago area until 11 a.m., according to the National Weather Service. In Chicago, the wind chill was as low as 18 below zero overnight. In Aurora, the wind chill dipped to 35 below early Monday.

There was likely to be a repeat of wind chill advisories Monday night and Tuesday morning, when temperatures will be even colder than Monday morning, with a likely low of about 10 below. It’s possible temperatures also could dip below zero Tuesday night or early Wednesday.