Het weer in Puerto Varas in december

Chile's forum is blunt that August is the depths of winter in the Lake District, with rain and generally unsettled weather more likely than not around Puerto Varas. Posters describing this region even in summer mentioned wild swings within a single day - sun and 70s F one moment, wind and rain in the 50s the next - so August's version of that same 'four seasons in a day' unpredictability, just colder throughout, is the realistic expectation. Layering up and packing genuine rain gear matters more here than picking the 'right' week.

Forum posters describe February - the heart of the Southern Hemisphere summer here - as typically bringing daytime temperatures in the low-to-mid-20sC with sun on most days, but posters are consistent that good weather is never guaranteed in southern Chile and genuinely 'four seasons in a day' is a real possibility, with wind and rain both worth packing for even at the height of summer. Posters recommend layering rather than committing to either warm-weather or wet-weather gear alone, since conditions can shift meaningfully within the same day. The Lake District's scenery (volcanoes, lakes, waterfalls) is named as worth the visit regardless of which version of the weather shows up on a given day.