It was still freezing in MN in may (it snowed while I was there then). I would guess even with the Astros if the weather is good, it will be closer to 33, since June 1 all the games have been 33+ including a game against Seattle. I went to a game last year, it is a nice park, not as nice as MM. The area around the park is great though, bunch of food and beer options. Not sure where you are staying, but they have light rail that dead ends into the stadium too.