Kato Nisi, Greece offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Kato Nisi is known for its proximity to the Monemvasia Castle and the beautiful beaches of the Peloponnese. The best time to travel to Kato Nisi, Greece, is from late May to early October, with average air temperatures ranging from 75-85°F (24-29°C) and water temperatures around 72-79°F (22-26°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!