Through July 14th, Chicago has seen only one 90 degree day.
The average number of 90 degree days does vary between O’Hare, Midway, & Northerly Island. O’Hare normally sees 14 days at 90 degrees or higher while Midway averages 15 days.
Due to the close proximity of Lake Michigan, Northerly Island averages 8 days of 90 degrees or higher.
The greatest number of 90 degree or higher days stands at 47 set back in 1988. The summer of 2012 saw 46 days at 90 degrees or higher with 4 of those days in the 100s.
Last summer (2014) only saw the mercury hit 90 degrees 3 times.
There is a chance that the upcoming weekend could squeeze out 2 days in the 90s, but thunderstorm chances could keep temperatures a few degrees cooler.
The 3 month outlook (July-September) from the Climate Prediction Center calls for temperatures, on average, to be slightly cooler than normal.