The best time to go to Inverarnan is during the late spring, summer, and early autumn months, from May to September, when the weather is generally mildest and the days are longest.May and June offer pleasant temperatures and fewer crowds, making it ideal for those who enjoy hiking and exploring the natural beauty of the Loch Lomond & The Trossachs National Park without the peak season bustle. The daylight hours are extensive, allowing for longer days out.July and August are the warmest months and are great for families. The lochs are at their most inviting for water activities, and local attractions are fully operational. While it's the busiest time, Inverarnan maintains a relaxed feel, and the extended daylight means more time for outdoor adventures.September provides a lovely transition with cooler, crisp air and the beginning of autumn colours, which are particularly stunning across the glens and hills.