https://chicago.cbslocal.com/2019/01...-extreme-cold/Temperatures on Wednesday are expected to be in the negative range all day, with a high of about 12 below, which would be the coldest high temperature on record for Jan. 30 in Chicago. Overnight lows will reach as low as 23 below zero, only a few degrees higher than the coldest temperature ever in Chicago, when it was 27 below on Jan. 20, 1985.