On February 17, Chicago’s 67-degree high broke the record of 62 set back in 1880. Where was the official thermometer located then?

Dear Tom,
On February 17, Chicago’s 67-degree high broke the record of 62 set back in 1880. Where was the official thermometer located then?
Tom Wagner, Yorkville

Dear Tom,
Chicago’s first full year of weather records dates back to 1871 and the 1880 record that fell on Friday was one of the oldest. At that time, the city’s official thermometer was located at the Roanoke Building on the southeast corner of Madison and LaSalle. It was the official weather observation site from June 8, 1873 until January 1, 1887 when it was moved to the Chicago Opera House on the southwest corner of Clark and Washington. Among the city’s longest-standing temperature records are record lows of minus 4 and minus 6 on December 4-5, 1871, a record high of 68 on December 31, and 65 on January 1 during the 1875-76 New Year’s holiday.