To find out, we've put together a chart showing Tom Brady's passing yards in each game, along with the weather conditions during that game as recorded in the official NFL gamebook:
Right away, Brady's big games in cold weather at Buffalo and against Philadelphia and Pittsburgh jump out--the cold weather didn't appear to have slowed Brady down much in those games (as least as measured by his yardage output). Similarly, the Pats' sack-drowning of Washington took place on one of the windier days of the season.
It's certainly true that, in general, Brady's passing yards are down since December. But given the big games Brady had in cold weather earlier in the year, it doesn't seem to makes much sense to chalk that up to the weather. Rather, a combination of opponents who were both fired-up and determined to cut down on the deep ball, and the Patriots' consquent increased focus on Laurence Maroney and the running game have combined to pull down Brady's ever so slightly.
So what does all this mean for the Super Bowl? Well, probably very little. It's true that the Super Bowl will likely be played in better weather than New England's other playoff games, or its previous game against the Giants--based on weather.com, it will probably be in the low 60's at kickoff.
But even if you ignore the above chart and assume that the Patriots do pass better in warm weather, it's tough to believe that the 15-20 degree difference between the first Giants game and the Super Bowl could have a measurable effect on the Pats--it's not as though it's going to be 85 out there. Moreover, given how well Brady threw the ball in the first game, it's tough to imagine that there's a whole lot of marginal upside for him in this game--exactly how many more yards can he throw for over and above the 355 he hung on New York last time?
So, for all of the above reasons, this meme doesn't pass the sniff test. Give it an A- for effort, but a D for accuracy. We figure that works out to about an 8 on the hype scale. Sorry, Bill.