You can expect sunny weather because sun is shining in Marmaris over 300 days per year! Pleasant swim in Marmaris is possible all year round, depending on preferences. Sea temperatures begin to rise in spring, reaching 20 degrees in May. March signifies the end of winter as the weather turns to Spring. In April temperatures reach up to 21 – 22 degrees Celsius. In May the days are sunny, and afternoons are hotter with an air temperature of around 25 C. August is the hottest month in Marmaris with an average temperature of 29 C (84°F) and the coldest is December at 6 C (43°F).