Jupiter, Romania offers 8 beaches perfect for sunbathing, surfing, swimming, and more. Constanta, Romania, is known for the historic Constanta Casino and the ancient Roman mosaic. The best time to travel to Jupiter, Romania, is during the summer months of June to August, when the average air temperature is around 25°C (77°F) and the Black Sea water temperature is approximately 23°C (73°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!