I went to the Steelers Miami game a few years back in the middle of a monsoon that ended 3-0 and the punt got stuck in the mud. It was voted the worst football game in NFL history.
I'm all for the elements, it makes for some tough football. But its also low scoring, low passing, pretty boring. I like cold weather for the "toughness" of the game, but I'd be lying if I said I didn't want a 90 degree perfect sunny day where teams can open up their playbook and really air it out.