Dear Tom,

When was the last time Chicago recorded seven or more 90s in a row?

—Cal Fredricks

Dear Cal,

It’s been a while. The city’s last 7-day run of 90s took place 5 years ago in late Sep. 2017, when highs of at least 90 were recorded from Sept. 20-27 (92,94,94,95,93,92,92). It was the city’s only 7-day run of 90s ever recorded in September. Prior to that was the 7-day heat wave from July 12-18, 2012, when highs reached 91,93,90,95,97,99 and 94. The city’s record-long run of 90s is 11, reached on four occasions, all during the 1950s, a decade characterized by hot summers and little air conditioning. Three runs occurred in consecutive summers, 1953, 1954, and 1955 and the fourth in 1959. The city’s 1988 drought summer that logged a record 47 days of 90 or higher (including 7 100s) boasted a 9-day run from July 27-Aug. 4 followed by a 7-day run from Aug. 11-17.