Dear Tom,

I remember going to school in the late 1970s and early 80s with below-zero temperatures day after day. What is the city’s longest stretch of below-zero days?

Bonnie M.  Evanston

Dear Bonnie,

Chicago’s longest string of below days is 10, logged more than a century ago in January 1912, the city’s second-coldest month on record. It averaged 11.9 degrees, second only to January 1977, which averaged 10.1 degrees. The prolonged run of subzero days began Jan. 4, with a low of minus-6, and continued through Jan. 13, when the low was one-below zero. The lowest temperature during the cold wave was minus-16 on Jan. 7, and the coldest day was Jan. 5, with a high of minus-5 and a low of minus-10. The city has also shivered through two three-day strings, in which the mercury never even reached zero, remaining below zero throughout the day: Dec. 23 to 25, 1983, and Jan. 21 to 23, 1883.