Lac Megantic, Canada offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Lac Megantic is known for the Lac Megantic Lake and the nearby Mont Megantic National Park. The best time to travel to Lac Megantic, Canada, is during the summer months of June to August, when the average air temperature is around 68°F (20°C) and the water temperature is approximately 66°F (19°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!