Cairns, Australia! If it's not bucketing down it's thinking about it. You need a hat like this.

A very light coated canvas makes up the cap and brim. Then we meshed half the sides (crown) so breeze can flow through while keeping the front of the head covered. We used a synthetic mono filament (real thick fishing line) to hold the brim which is pliable enough to folds away when you are traveling. Other features are the three strand hand braided hat band with back tassels and draw corded chin strap.