Lake Annecy in August

May through October offers the best weather, with July and August bringing peak crowds and 25°C temperatures perfect for swimming. June hits the sweet spot — warm enough for lake activities but before the summer rush drives up prices. September delivers my favorite conditions: still swimmable water, autumn colors starting in the mountains, and significantly fewer tourists. October can be gorgeous for hiking, though some mountain lifts close after mid-October. Winter transforms the area into a quieter, more contemplative destination, though many lakeside restaurants shut down from November through March. Here's what nobody tells you: morning fog often blankets the lake from October through April, creating mysterious but photo-challenging conditions. If you're chasing those perfect reflection shots, visit between June and September when clear mornings are most reliable.