When are Chicago’s “beautiful days” most likely to occur?
Assuming a "beautiful day" in Chicago is warm with highs in the mid-seventies, cloudless skies and low humidity, when are such "beautiful days" most likely to occur?
Christopher Damon, Oak Park
Chicago’s picture-perfect days, can occur anytime between March and November, but are most likely in May and early October. When unseasonable warmth occurs in Chicago in late winter and early spring or late fall and early winter, it is usually delivered by strong and gusty winds disqualifying it from the “beautiful day” terminology. However in May and early October temperatures in the middle 70s are easily achieved without the strong winds and the absence of summer’s uncomfortably high dew points. Chicago climatologist Frank Wachowski notes that October leads the year with highest percentage of totally sunny days while May ranks fourth.