Littleton, United States offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Littleton, Colorado, United States, is known for the Littleton Museum and its charming historic downtown area. The best time to travel to Littleton, United States, is during the summer months of June to August, when the average air temperature is around 70-85°F (21-29°C) and water temperatures in nearby lakes are typically 65-75°F (18-24°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!