You are going to get wet. Most people simply accept that as shown in the first photo on the previous page. However, it can get a bit chilly, never cold, but a bit chilly if you are having a break or doing an easy walk while it's raining. A heavy raincoat is weight you don't need but a lightweight (about 50 g) plastic poncho can be worth while. I (Russell Willis) always carry a small poncho on wet season trips. I've used it once. I went through every digital photo I had. The only one with someone wearing a poncho is the one at right. I can't recall ever having seen someone wearing a normal raincoat on a Top End or Kimberley trip.