I love hot weather, but it seems like we have to wait for mid-summer to get a strings of 90s. What has been the city’s earliest-in-the-season heat wave?
—Brittany F. Richton Park
Defining a heat wave as three 90-degree days in a row, the city seldom experiences one until June or July, and it some years never records even one. Chicago’s earliest on record heat wave occurred back in May, 1949 when four straight 90s occurred from May 3-6 with highs of 91 ,91, 94 and 91. More seasonable weather followed with highs dropping back to the upper 50s and 60s, before the mercury soared to 89 on May 17. The summer of 1949 went on to produce a total of 30 90-degree days with the four in May, eight in June, eleven in July and seven in August. In a typical summer, the city records 17 90-degree days at O’Hare and 23 at Midway Airport.