Sinapalu, Northern Mariana Islands offers 1 beach perfect for sunbathing, surfing, swimming, and more. Sinapalu, Rota Island, Northern Mariana Islands, is known for the stunning natural attraction of the Rota Latte Stone Quarry. The best time to travel to Sinapalu, Northern Mariana Islands, is from December to June, with average air temperatures around 80°F (27°C) and water temperatures near 82°F (28°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!