Arcadia, United States offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Arcadia, Washington, United States, is known for the Olympic National Park. The best time to travel to Arcadia, United States, is in the spring (March to May) when the average air temperature is around 70°F (21°C) and water temperature is approximately 65°F (18°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!