Darwin, unlike other areas of Australia, has two very distinct seasons that are quite different. Unlike "winter/summer" in many areas of the world, Darwin is divided by "wet/dry" seasons. It's consistently hot and sunny year-round - although temps in the summer months (Nov-Feb) can reach scorching highs. At the same time, during the extreme heat comes extreme wetness - the Wet Season runs from November to April and it can get very, very heavy at times. If you want to stay dry and avoid some of the hotter temps (the coolest months are June and July and it can even get as low as about 55 degrees - talk about a cold spell!), May through September is generally the best time to visit Darwin.

Darwin's a tropical city, so you're going to want to enjoy the sunshine and enjoy the outdoors - so when in doubt, book your ticket in the low season. You'll save money in airfare, too!

Bureau of Meteorology - Northern Territory Weather & Warnings Info

The downside is that during the Dry season it is very popular with tourists so accommodation can be a problem if it is left too late. If you are travelling out to Kakadu or the Litchfield National Park then at the start of the Dry (May) the countryside is still green and there is water in the creeks. By September it is drying up and the vegetation is brown or burnt and the creeks are drying up. By November it is humid and some new growth is starting. Thunderstorms are starting to occur and at night there can be some spectacular lightning displays. Camping out at this time of the year can be uncomfortable at night. By January the monsoon has generally arrived and it will rain often daily but it will only last for an hour, the rain cools the ground until the sun comes out then it becomes steamy again.