Dear Tom,
I was curious: How many days in the 138 years of records have had the same high and
low for a given day.
Cole Turgeon, Brookfield
Dear Cole,
Such days are rare, but they do occur. A computer sweep of Chicago's official
temperature data base from Nov. 1, 1870, through Dec. 31, 2008--that’s 50,465
days--reveals only three days on which temperatures remained absolutely steady
through the entire 24-hour day: March 13, 1878, when the city's official thermometer
registered a constant 44 degrees; March 24, 1891, with 32; and Feb. 6, 1942, with 35.
The range between the city's maximum and minimum temperatures was only 1 degree
on an additional 24 days, most recently six years ago on April 8, 2003, when the high
and low temperatures were 32 and 31 degrees.
