I am Canadian and am not sure spending 4 months in Canada is what I would recommend. There is a huge interesting world out there.

But Canada IS amazing and diverse and you will love it.

We are just coming into our winter and that makes outdoor water activities impossible and hiking etc more difficult.

But no need to wait. My suggestion is to come very soon. Work in BC at a ski resort until the spring and then start your travelling. As an Australian you can legally work in Canada for up to a year I think. It would be a great way to break of the corporate rat race.

As to specifics, it really is time of year dependent and if you want to be a tourist experincing Canada outdoors, you really are better off coming in June to September. Yes winter has its own awesomeness but you'd appreciate summer more.