Summer's start is not an astronomical event, but it's easy to think so. After all, the
summer solstice (an astronomic event that occurs this year on June 20) marks the official
start of summer. In the atmospheric sciences, however, summer is the three- month
period that began on June 1. But climatologically, the warmest quarter of the year at
Chicago is the 91-day period that begins today. With an average temperature of 73.5
degrees, June 11 through Sept. 9 is Chicago's summer -- its warmest 91 consecutive
days.
JUNE: WETTEST MONTH IN WETTEST SEASON
Summer is also Chicago's wettest season and, at Midway Airport, June is summer's (and
the year's) wettest month. Normal June rainfall, 4.16 inches, accounts for 11 percent of
the city's annual total. With 4.00 inches as of June 10, nearly all of the full month' s
normal allotment has already come down.
--By Richard Koeneman, WGN Weather Center Meteorologist
