These seasons are so much more descriptive and relevant than trying to make the European Spring, Autumn thing fit. Monsoon time, continuous low cloud and heavy rains. SE trades reestablish. Cool nights, morning mists. Thanks to Jane O'Neill for supplying the above information.
Rainfall is quite variable from south to north.
Practically all rain comes in the wet season of the monsoon, that being, November to April. The months May to September being rainless except for light isolated showers on the north east tip of Arnhem Land where the otherwise dry south east trades have picked up some moisture as they crossed the Gulf of Carpentaria. Thunderstorms average 40 - 50 per annum in the south but increase to around 90 per annum in the Darwin area. Most thunderstorms come in the October - April period. Some severe wind squalls may occur with the storms.