T.H.
I haven't lived in Chicago for a while, so I"m sure you'll get better responses from others who currently live there, but honestly, it's either cold or blazing hot! So, bring layers. This summer, after June, it will be hot. If you're going in June, you never know what you'll get. Good walking shoes are a must. I think tennis shoes are great, but I'm just as comfy walking around in my Teva flip flops as anything else. I think it depends on what you're comfortable in. The city blocks are long and it's just pavement so it can be hard on the feet and knees after a while. It's a great city though and tons of fun...plus the food is generally amazing! There are a lot of good dive type places as well as some super amazing chefs that own restaurants there! Have fun!