For those of you saying Arizona, don't forget that Chase Field has a retractable roof and air-conditioning.

No sources, this is a 100% assumption.

I'd say that Coors Field gets the coldest (Colorado) and Chase Field gets the hottest (Arizona).

Well for all year around, probably any of the New York teams, but in the middle of the summer, it stays cooler in Seattle than any other city.

As for hottest I would have to say either Arizona or Florida.

Coldest would probably be Seattle. Hottest would probably be Florida MArlins. You have to consider that you can only real;ly account for OPEN stadiumsm, and not domes, as domes are air conditioned...

Chicago, Boston, and New York get pretty cold in the postseason, also they are also outdoor stadiums (Seattle has a retractable roof) I'd think that Miami where the Marlins play would be nothing but hot and sticky in the summer.

toronto and arizona. either way the temperature extremes would stink if you had to play those two teams back to back