South Glengarry, Canada offers 1 beach perfect for sunbathing, surfing, swimming, and more. South Glengarry is known for the historic site of the Glengarry Cairn and the scenic beauty of the St. Lawrence River. The best time to travel to South Glengarry, 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 in nearby bodies is approximately 68°F (20°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!