The books closed at midnight on the warmest September ever recorded at Midway Airport. The month averaged 71.4°—an impressive 5.5 degrees above the long-term average since 1928. Midway’s urban environment permits less cooling at night than that which occurs in the more suburban surroundings near O’Hare on the city’s Northwest Side. Over the course of a year, studies have shown this produces a temperature spread of nearly 2 degrees between the two sites. That sort of temperature variation was certainly evident in the O’Hare data collected in September. There, the month finished quite warm (69.4°)—a reading 5.6 degrees above normal. But that average only ranked 14th warmest of 135 Septembers on record at the city’s various official sites over the years.
State climatologist Dr. Jim Angel reports Illinois’ monthly temperatures statewide ranked fourth warmest of all Septembers on the books since 1895.
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
