You wouldn’t know it from Friday’s comfortable weather but Chicago is entering a period of the year known for its 90° highs. Friday’s highs are predicted to remain in the 70s—specifically, 77° at O’Hare. That’s “cool” for this time of year.
The “normal” high—the smoothed average of the highs observed on this date from 1971-2000—is 84°. That puts today 7 degrees below normal.
Nearly a quarter of the city’s 90°-plus temperatures—488 of the 1,876 on the books at Midway Airport since 1928—have occurred between July 11 and 31. Daily highs reach or exceed 90° nearly a third of the time in July’s back half. Weather records indicate Chicagoans encounter the best odds of experiencing a 90° high on July 20 with a 38 percent historic probability, followed by July 19 with a 37 percent chance.
Thursday’s 80° high was the 42nd reading at or above 80° to date this year—the most here by July 12 in 16 years.
--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.
