Getting to be late for Chicago to not have recorded a high of 85+ yet. The record latest is July 3 back in 1935. I don't think that record will be broken but let's see how many more days it will take.
First 85+ high:
June 19: 1893, 1924, 1997, 2009
June 22: 1882
June 23: 1884
June 30: 1878
July 2: 1883
July 3: 1935