Saint Jean de Monts, France offers 5 beaches perfect for sunbathing, surfing, swimming, and more. Saint Jean de Monts is known for its expansive sandy beaches and the Saint-Jean-de-Monts Forest. The best time to travel to Saint Jean de Monts, France, is from June to September, when the average air temperature is around 20-25°C (68-77°F) and the water temperature is approximately 18-21°C (64-70°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!