Middletown Township, United States offers 10 beaches perfect for sunbathing, surfing, swimming, and more. Middletown Township, New Jersey, United States, is known for the Sandy Hook Gateway National Recreation Area. The best time to travel to Middletown Township, United States, is in late spring (May to June) when the average air temperature is around 65-75°F and water temperature is approximately 60-65°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!