Killarney, Canada offers 5 beaches perfect for sunbathing, surfing, swimming, and more. Killarney, Ontario, Canada, is known for Killarney Provincial Park and the stunning La Cloche Mountains. The best time to travel to Killarney, Canada, is during the summer months of June to August, when the average air temperature is around 20°C (68°F) and the water temperature is approximately 15°C (59°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!