What is the city’s record for the most consecutive sub-60-degree days in May?
Chicago climatologist Frank Wachowski searched the record books and found that the 13-day sub-60 string in May 1917 is the city’s longest. The streak actually ran 22 days, beginning back on April 22. After the streak ended on May 14 when the mercury climbed to 68, a rapid warm-up followed with the high temperature soaring to 87 on May 17 and 88 on May 19. That prolonged cool spell was greatly influenced by the downtown location of the official thermometer near still-chilly Lake Michigan. Post- July 1942, when the city’s official thermometer was moved inland, first to Midway Airport and then to O’Hare, the streak shrinks dramatically to seven days, logged on three occasions, May 7-13, 1943, May 8-14, 1966, and May 1-7, 1978.