A storm breaks over a floodplain in the Top End Photo © Martin Armstrong, PWCNT
Darwin-Kakadu is one of the most northerly regions of the tropical savannas where periodic summer storms and tropical cyclones deliver most of the annual rain. Variability of rainfall is low to moderate but the mean annual totals diminish from 1600 mm along the coast to around 800 mm further south.
The wet season monsoonal winds originate in equatorial regions and move in from the north-west across the coast bringing hot, humid, unstable conditions. Thunderstorms can be prolific along the coast with an average of 60 to 80 thunder days each year which become less frequent further south.
Humidity is very high through January with average readings from 50 to 80 per cent. Extensive cloud cover reduces the annual average daily hours of bright sunshine. However, average temperatures inland at this time are 36ºC with a cooler 33ºC or less along the coast. Climate discomfort days increase in number from 150 to 200 in a southerly direction.
The dry winter season is generally rainless with mild to warm conditions. Average minimum temperatures in July are between 15 and 21ºC with the cooler temperatures being experienced inland and to the south. Winds flow in from the south-east bringing some moisture picked up from the Gulf of Carpentaria but are generally dry. Humidity levels are low, averaging between 20 and 60 per cent in July.