Saint Mandrier sur Mer, France offers 6 beaches perfect for sunbathing, surfing, swimming, and more. Saint Mandrier sur Mer is known for its picturesque harbor, beautiful beaches, and the nearby Cap Cepet peninsula. The best time to travel to Saint Mandrier sur Mer, France, is from June to September, when the average air temperature is around 75°F (24°C) and the water temperature is approximately 72°F (22°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!