So far this season we’ve been focusing on the lack of snow. What are the odds of a subzero-free winter? What are the city’s earliest and latest subzero occurrences?
Thanks, Tom Gregg, Niles
Most Chicago winters record subzero temperatures, with a typical winter season averaging eight days with negative readings. Checking the city’s climate records dating back to the winter of 1870-71, there have been just 13 winters without one, most recently the winter of 2011-12. The winter with the most subzero days was back in 1884-85 when 25 were recorded. The city’s earliest subzero day was on November 23, 1950 with a low of minus 1. The latest was also a low of minus 1 on March 22, 1888. Chicago’s last below zero day was on Valentine’s Day February 14, 2021 when the mercury dipped to five below zero.