Big Arm, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Big Arm, Montana, United States, is known for its proximity to Flathead Lake, one of the largest natural freshwater lakes in the western United States. The best time to travel to Big Arm, United States, is during the summer months of June to August, when the average air temperature is around 70-80°F and the water temperature is approximately 65-70°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!
