Polk City, United States offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Polk City is known for Saylorville Lake and Big Creek State Park in regard to tourism. The best time to travel to Polk City, United States, is in March when the average air temperature is around 70°F (21°C) and the average 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!