Trstenik Beach offers excellent swimming conditions with clear, clean water that's well-regarded among Split's urban beaches. The pebble bottom provides good visibility, and the gradual entry makes it suitable for families with children, though water shoes are advisable. The beach's location in the hotel zone means it's well-maintained and regularly monitored. Beach clubs in the area often have facilities and staff present during summer months. While not always staffed with lifeguards, the populated setting and nearby amenities add to overall safety. Standard supervision of children is recommended, especially on pebbles.

Trstenik Beach is accessible year-round, with peak season from June through September offering the warmest water and full beach club services. July and August see the most visitors but maintain a pleasant atmosphere thanks to the beach's good length and organization. For optimal conditions with fewer crowds, visit in June or early September when weather remains excellent. The beach's hotel-zone location means facilities operate throughout the tourist season. Early summer and early autumn offer comfortable swimming temperatures. Even in shoulder seasons, the promenade and nearby amenities remain accessible for sunbathing and seaside walks.