Sudden Valley, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Sudden Valley is not widely recognized for travel and beach tourism. The best time to travel to Sudden Valley, United States, is during the summer months of June to August, when the average air temperature is around 70-75°F and the water temperature is approximately 65-70°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!