Dear Tom,
When was the last time it was 100 degrees in Chicago?
— Kiley Reed
Dear Kiley,
Chicago’s last encounter with triple-digit heat was four years ago during an extended period of hot weather in late June and early July 2012. A harbinger of heat to come, the city’s official thermometer at O’Hare International Airport reached 100 on June 28, marking the city’s first 100-degree day since July 24, 2005, when it reached 102 during a very hot Lollapalooza concert. A week later, the city recorded a record-tying high of 102 on the Fourth of July followed by back-to-back highs of 103 on July 5-6.
It was even hotter at the lakefront, where the mercury soared to 105 degrees at Northerly Island on July 5. Heat-related power failures caused problems in the city and even forced the Shedd Aquarium to close. Other locations reaching 105 during that heat wave included Midway Airport, Chicago Botanic Garden and Rockford.