Chicago’s weather records have come from several places since their inception. They’re at O’Hare now, but what other locations have been used?
— Gary Walters, Chicago
Chicago’s “official” weather records — those that constitute the database from which the city’s normals, means and extremes are calculated — have been taken at four primary locations: downtown Chicago, the University of Chicago, Midway Airport and O’Hare International Airport. Chicago’s continuous weather observations date from Oct. 15, 1870, when a federal weather office was established at 181 W. Washington St. under the jurisdiction of the U.S. Army Signal Service. The office was located at several downtown locations through Dec. 31, 1925, then at the University of Chicago through June 30, 1942, then at Midway Airport through Jan. 16, 1980, and at O’Hare since then.