A February cold spell of Thursday’s intensity is long overdue. Though not even close to the +1° high on this date 102 years ago—the coldest Feb. 17 daytime reading on record in 135 years of official weather observations—today’s 25° high is the first February maximum temperature which has failed to reach 30°. Eight such days had occurred by this time last February and an average of nine readings below 30° have occurred in February since 1871. It’s the coldest daytime temp to grip the city in two and a half weeks. In a winter noteworthy for the limited number of truly frigid days, a 25° Thursday high would rank among the 15 coldest temps since Dec. 1.
The chill occurs in the wake of a jet stream shift. Upper steering winds are blowing into the Midwest from the NW. The air which has arrived in Chicago Thursday originated over Duluth, Minn. and Winnipeg, Canada 24 hours ago.
-Tom Skilling
