It's impossible to predict the weather if you are traveling to Patagonia (That's what makes it so exciting). We never completely trust the weather prediction because you can feel 4 seasons in one day. The wind coming off the southern ice field creates a very erratic and unpredictable weather pattern. So, the best way to enjoy your time in Patagonia is to be prepared and bring layers. This brings a whole new meaning to "layers". If you are looking at weather online, Windguru.