Sremska Mitrovica, Serbia offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Sremska Mitrovica is known for the ancient Roman city of Sirmium. The best time to travel to Sremska Mitrovica, Serbia, is in late spring (May to June) when the average air temperature is around 20-25°C (68-77°F) and the water temperature in nearby rivers is approximately 18-22°C (64-72°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!