Dear Tom,
What is the official record for Chicago’s longest duration of consecutive days under 40 degrees in the month of November?
— Gary Alperin, Elk Grove High School
Dear Gary,
We posed your question to Chicago climatologist Frank Wachowski, who provided the following information. Checking the city’s official station records dating to 1871, the city’s longest string of sub-40-degree days in November is 17, established Nov. 14 to 30, 1880. During that prolonged early-season cold spell, the warmest day was Nov. 27, when the high reached 39. Nov. 21 brought historic cold with a record low maximum of just 11 and a frigid early-morning record low of 1 above zero. The string of sub-40 days broke at 19 on Dec. 3, when the high temperature finally reached 40 — and by Dec. 5 it had warmed to a balmy 50.
