Miseno, Italy offers 1 beach perfect for sunbathing, surfing, swimming, and more. Miseno, Campania, Italy, is known for the ancient Roman site of the Piscina Mirabilis. The best time to travel to Miseno, Italy, is from May to September, when the average air temperature is around 75°F (24°C) and the water temperature is approximately 73°F (23°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!