The best time to go to Wellesley Island is during the summer months, from June to August, when the weather is warm and all attractions are fully operational.During this period, temperatures are ideal for enjoying outdoor activities like boating, fishing, and exploring the Thousand Islands. You'll find all the local shops, restaurants, and tour operators, including those offering Boldt Castle tours, open daily. This is a great time for families seeking a classic summer vacation with plenty of activities for all ages, from swimming at local beaches to mini-golf.For couples looking for a slightly more tranquil experience with pleasant weather, late spring (May to early June) or early fall (September to early October) can also be excellent. During these shoulder seasons, the crowds are thinner, but most attractions are still accessible on a more limited schedule, and the natural beauty of the Thousand Islands is particularly striking with spring blooms or fall foliage.