What is the average number of 90-degree days in May in Chicago?
Of the 93 Mays in the period 1928-2020, 46 of them recorded no reading of 90 degrees or higher during the month of May at Midway Airport. Of the 47 Mays that did record at least one 90-degree day in May, 1977 registered the greatest number with 10 days. The average number of days at or above 90 degrees in May is 1.2 days. Looking at the entire year, 23.4 days per year experience daytime high temperatures of at least 90 degrees. The greatest number of 90-degree or higher days was 48 in 1988. That number, 48 days, is also the greatest number in all years in Chicago in the period beginning with 1871. The number of 90-degree days per year is somewhat lower near Lake Michigan.