Cairns and tropical north Queensland have just two seasons: wet and dry. The monsoon season hits during the austral summer, between December and March, and the dry season comes during the winter, from June to August.
Winter is peak season for good reason: Aside from high prices and big crowds, it allows for better access to some of the more remote wilderness areas, which can get rained out during the monsoons. The mild weather stays tropical and comfortable, though nights sometimes prove a little chilly.
Summer is another story: It gets hot, muggy, buggy, and wet. On the plus side, the abundant precipitation is a boon for whitewater rafting on swollen rivers; surrounding rainforests become especially lush and green; and wildlife comes out in force. A minus? The influx of box jellyfish, called “stingers,” along Cairns’s nearshore waters. But you don’t necessarily need to stay out of the water: A wetsuit can provide protection against the tentacles, and most popular beaches have stinger nets in place to keep the potentially deadly pests away from swimmers.
In April and May, the weather can still be hot and muggy, and there’s often a chance of rain showers. But traveling during the shoulder season can offer a reasonable compromise between the crowds of winter and the extreme weather of summertime.