During the late January cold spell, much was made about possibly having the lowest daily maximum temperature recorded in Chicago. Let’s turn the question around: What has been the city’s highest minimum temperature?
Chicago’s highest minimum temperature was a stifling 85 degrees, recorded more than a century ago, on July 29, 1916. It occurred during an extended heat wave when the city’s official temperature failed to drop below 80 degrees for 147 hours during the July 25-31 period and the high temperature climbed as high as 102 degrees. Overnight lows that remain in the 80s are extremely rare in Chicago, having occurred at the official station on only 32 days since records began back in 1871. Last summer the city logged one occurrence, a low of 80 degrees on June 30.