Dear Tom,
The recent big temperature drop prompts me to ask what our all-time largest 24-hour
temperature drop might be.
Tim Bonham, Chicago
Dear Tim,
Huge temperature fluctuations are among the defining characteristics of Chicago's
vigorous climate. From Monday into Tuesday area residents experienced a 24-hour
temperature collapse from the low 80s to the low 40s. The city's largest-ever
temperature decline dwarfs that 40-degree tumble, however. At 4 p.m. on Nov. 11,
1911, Chicago's temperature peaked at 74 degrees, a record high for the date. Then,
readings plunged as arctic air surged in. By 12:30 p.m. on the 12th -- 20 1/2 hours
later -- the temperature was 13 degrees.
From one afternoon to the next, Chicago's temperature had crashed 61 degrees, a
tumble that still stands as the city's largest 24-hour temperature change.
