The NFL is unlike many other sports in that the weather plays a major role. Throughout the history of the league, there have been a ton of games impacted by terrible weather. The only weather event that would cancel an NFL game is a lightning storm, though some games have been postponed due to the anticipation of bad weather.
NFL teams have played through blizzards, heavy rains and bitter cold. Today the Jacksonville Jaguars and Carolina Panthers are dealing with extreme rain. Being dubbed the "Monsoon Bowl," it has resulted in a very sloppy game.
The following slides will reveal some of the worst weather games in NFL history. I am sure there are a ton of people out there who vividly remember these games.