Chicago’s suddenly milder temperatures and decidedly stronger southeast winds Friday can’t hide the fact the clock is ticking toward winter’s official (astronomically determined) open. Winter Solstice takes place just after midnight at 12:08 a.m. Saturday morning—the point at which the sun’s most direct rays fall as far south on the planet as at any time of the year. Winter begins with the year’s shortest day in the northern hemisphere. Sunlight is just one-fifth the strength of June sun in Chicago, with just over 9.1 hours of daylight. The good news is days here begin to lengthen gradually and more than 5 hours of daylight will be added by the time summer begins in June.
A rare December Air Pollution Action Day has been declared by the Illinois EPA Friday. Air quality slipped to unhealthful levels at a number of Chicago area sites Thursday.
--By Tom Skilling, WGN-TV Chief Meteorologist
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
