Istres, France offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Istres is known for its proximity to the beautiful beaches of the Mediterranean and its scenic natural surroundings. The best time to travel to Istres, France, is from June to September, when the average air temperature is around 25°C (77°F) and the water temperature is approximately 22°C (72°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!