Having a son who grew up in Chicago, and now plays JUCO baseball in AZ, I will tell you that the kids from the warmer area's don't work at the game as hard as the players from the "cold" area's. They aren't as fundementally sound and they complain about the weather MORE. He loves that he is outside in shorts and a t-shirt...on a field in January..but he has called out a team mate or two for not wanting it bad enough or not working hard enough to make a change.
I have heard coaches there say that they would take a kid from a cold climate over one from a warm climate, all things being equal...because the cold climate kid will out work and out hustle the warm climate kid....and I agree with that. I am not saying that all warm climate kids are lazy...but I think you you were to look at the players...day in and day out...you'd see the difference. The only advantage the warm weather players have is that they can play more...but work less on fundementals
Just my opinion from what I have seen over the last year