Town Of Alexandria, United States offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Town Of Alexandria, New York, United States, is known for the Thousand Islands region and Boldt Castle. The best time to travel to the Town of Alexandria, United States, is in late spring (May), when the average air temperature is around 70°F (21°C) and the water temperature is approximately 60°F (16°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!