Marquis, Grenada offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Marquis, Saint Andrew, Grenada, is known for the Grand Etang National Park and Forest Reserve. The best time to travel to Marquis, Grenada, is from December to April, with average air temperatures around 82°F (28°C) and water temperatures near 80°F (27°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!