Looking at upstream obs and the short range guidance, there is a chance of getting a -30 dewpoint at ORD later. The only day in the past 30 years to achieve that was 1/30/2019, when the dewpoint bottomed out at -32.
In case anyone is wondering, the last time that the dewpoint got lower than -32 in Chicago was on 1/20/1985 (a day better known as being the coldest day on record for the city). The dewpoint reached -39 on that day.