Great Barrier Reef Weather

Knowing the Great Barrier Reef weather conditions is a big part of planning your Australia travel, so it’s good to know that it’s warm year-round in the tropical North Queensland region and the most popular bases for snorkelling and diving trips, Cairns and Port Douglas.

With the sea and air temperature still warm in winter (May to October), this tends to be the drier season, with more rain falling in the hotter summer months between November and April.

Here’s some more detail about the four seasons you’ll encounter if you’re planning Great Barrier Reef travel.


December – February | Average water temperature 29°C (84°F)

This is usually the wettest time of the year and can be accompanied by tropical thunderstorms and possibly a tropical cyclone. The air and water temperatures and humidity are at their highest during these months.

Book a summer Great Barrier Reef snorkel and dive trip


March – May | Average water temperature 26°C (78°F)

Conditions remain warm in autumn, but there is generally less rain at this time of year. The water temperature starts to drop and the evenings begin to cool down to about 20°C (70°F). Visiting the Great Barrier Reef at this time of year is a great opportunity to see juvenile fish.

Book an autumn Great Barrier Reef snorkel and dive trip


June – August | Average water temperature 24°C (75°F)

This season offers pleasant conditions, with low humidity, clear skies and very little rain. The water temperature is at its coolest at this time of year. This is also the most likely time to see Minke and Humpback whales during their migration. Join us for a Great Barrier Reef minke whale experience over these months.


September – November | Average water temperature 27°C (80°F)

During this period, everything starts to warm up. By the end of November you will be experiencing more humid weather and maybe an afternoon thunderstorm to cool things down. The water temperature is usually warm enough to dive without a wetsuit if you wish. The best place to be is in the water, spending balmy evenings on the Great Barrier Reef and watching the sunset.

This is also coral spawning season. This is an amazing phenomenon to witness while snorkelling and diving. Under cover of darkness, all the corals on the reef spawn at once, making the reef resemble a snow globe!

Cairns Temperatures by Month

Cairns Average Rainfall