El Calafate in September

Peak season runs October through March when the weather is warmest and all tours operate daily. December and January bring 18-hour days and temperatures that actually hit 70°F, but also crowds and prices that'll make your wallet weep. November and March offer the sweet spot – decent weather, fewer tourists, and shoulder season rates. The glacier looks spectacular in any season, but winter visits (April-September) mean shorter days, brutal cold, and limited tour options. Some estancias and boat trips shut down completely. Here's what nobody tells you: the weather changes fast in Patagonia. Pack layers even in summer because that sunny morning can turn into a 40-mph wind storm by afternoon. The best glacier viewing happens in the morning when the light hits the ice just right, so book early tours regardless of when you visit.