Serj, Lebanon offers 1 beach perfect for sunbathing, surfing, swimming, and more. Serj, Mount Lebanon, Lebanon, is known for the Jeita Grotto, a stunning natural limestone cave system. The best time to travel to Serj, Lebanon, is in the spring (April to June) when the average air temperature is around 20-25°C (68-77°F) and the Mediterranean Sea water temperature is approximately 18-22°C (64-72°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!