Saint Jouan des Guerets, France offers 1 beach perfect for sunbathing, surfing, swimming, and more. Saint Jouan des Guerets is known for its proximity to the historic city of Saint-Malo and the scenic Rance River. The best time to travel to Saint Jouan des Guerets, France, is from June to September, when the average air temperature is around 18-22°C (64-72°F) and the water temperature is approximately 16-19°C (61-66°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!