Hot weather on Memorial Day

Dear Tom,
How often do we reach 90 degrees or higher on Memorial Day?
Nick Recchia, River Grove
Dear Nick,
With its late-May occurrence, Memorial Day is celebrated before Chicagoas
weather usually turns hot. Prior to 1971 it was observed on May 30 and since
then on the last Monday in May. Since 1871 the official Chicago temperature
has reached the 90-degree mark on Memorial Day in only eight years, most
recently in 2006 when it climbed to 91 degrees on May 29. The high
temperature on the holiday has never been higher than 93 degrees, a reading
recorded twice, first in 1942 and again in 1953. In reality, many Memorial
Days in Chicago are quite chilly, putting a damper on holiday picnics and
outdoor celebrations. The high temperature has failed to reach 60 degrees on
22 Memorial Days including two very chilly holidays (42 degrees in 1889 and
46 degrees in 1894) when the mercury failed to get out of the 40s.