Do December, 1983, and March, 2012, have the greatest temperature departures from normal since records began in Chicago in 1871?
They do not have the greatest departures from normal, but they do rank high. December, 1983, was a bitterly cold month. With an average temperature of 14.3 degrees, it stands as Chicago’s coldest December on record. The average temperature in December is 27.7 degrees, so December, 1983, was 13.4 degrees below normal. However, January, 1880, holds the record for the greatest temperature departure from normal. With an average temperature of 39.8 degrees, it was 16.0 degrees above the January average of 23.8 degrees. March, 2012, was Chicago’s warmest March on record, with an average temperature of 53.5 degrees, or 15.6 degrees above the March average of 37.9 degrees.