Grosse Ile, Canada offers 5 beaches perfect for sunbathing, surfing, swimming, and more. Grosse Ile is known for the Grosse Ile and the Irish Memorial National Historic Site. The best time to travel to Grosse Ile, Canada, is during the summer months of June to August, when the average air temperature is around 70°F (21°C) and the water temperature is approximately 64°F (18°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!