Dear Tom,

Has Chicago ever had three 90-degree days in a row in the first half of May?

—Chuck Kennell

Dear Chuck,

It has. While the city’s early-May heat wave is extremely rare, it is not unprecedented. Back in 1949, Midway Airport officially logged four straight 90s from May 3-6 with highs of 91,91,94 and 91. Even more unusual were the back-to-back 90-degree highs reached on April 10-11, 1930, recorded at the city’s official downtown site at the U.S. Courthouse at 219 S. Clark St. The 1949 warm season produced a total of 30 days of 90-degrees or higher, well above the city’s current averages of 17 at O’Hare and 21 at Midway. Chicago’s all-time record for the most 90-degree plus days in a year is 48, established in the drought summer of 1988, a total that included seven days with triple-digit highs—the hottest day 104 degrees on June 20.