Sidi Mahrsi, Tunisia offers 1 beach perfect for sunbathing, surfing, swimming, and more. Sidi Mahrsi, Nabeul, Tunisia, is known for its beautiful beaches and proximity to the historic city of Nabeul. The best time to travel to Sidi Mahrsi, Tunisia, is from May to October, with average air temperatures ranging from 25°C to 30°C and water temperatures around 22°C to 26°C. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!