The unseasonably mild air in place Thursday morning has only hours to run. A cold front settles south across the city mid-morning and by lunch time, NNE winds should have temperatures in the first stages of a downward spiral likely to carry readings through the 50s. It’s a cool-off which marks the end of the area’s brief flirtation with mild air in a remarkably chilly autumn season. In only four years since official records began here in 1871 has Chicago’s average temperature since Sept. 1 been colder. Feedbacks from the season’s sub-par temperatures are everywhere. Lake Michigan is running 8° cooler than a year ago while temperature data suggests home heating may have surged as much as 72% over the same period a year ago. Days with 70° or warmer highs are down 37% while chilly sub-50° days since September’s open have surged from one a year ago to 11 this year.
-Tom Skilling
