With the Montauk Chamber of Commerce’s annual Fall Festival this weekend, the end of summer is now official. And this chamber knows how to send out a season. There will be fireworks by Grucci, a clam chowder contest with over 30 restaurants vying for the title, live music, beer and wine tastings, clams and oysters, German-style food, a farmers market, games, inflatable jumps, face-painting, pumpkin-decorating, crab races, a 30-horse carousel, and more — lots more.