For the Chicago area, the number of 90 degree days varies by station and proximity to the lake. Lakeshore communities, especially along the Northshore see the fewest. Southwest and south suburbs see the most.
Average number of 90F/32,2C days in Chicago
Chicago/Lakefront: 12
ORD (10 miles from lake): 17
UofC (2 miles for lake): 18
MDW (9 miles from lake): 24
UofC and MDW have strong UHI's. ORD resembles many north suburban stations.
Some suburbs
My suburb (south): 28
Marengo (northwest): 20
North Chicago ( north near lake): 11
Antioch (north): 14
Barrington (north): 12
Joliet (southwest):30
Naperville (southwest): 26
Aurora (west): 21
Elgin (west): 17
Streamwood (west): 28
Rockford (northwest outlying): 28
I would like at least 35 days of 90 degree weather