The best time to visit Lake Sumner is during the spring and autumn months, specifically from April to May and September to October.These periods offer comfortable temperatures, typically ranging from 15°C to 25°C, which are ideal for outdoor activities like fishing, boating, and hiking without the intense heat of summer. You'll also find the lake and surrounding areas are less crowded compared to the peak summer season, making for a more relaxed experience.For those interested in water sports and swimming, late spring and early autumn still provide pleasant water temperatures. The gentle breezes during these months are also great for sailing or paddleboarding.If you're primarily interested in fishing, both spring and autumn are excellent. The fish are generally more active during these cooler periods, increasing your chances of a good catch.