Great Barrier Reef Weather

Great Barrier Reef weather is constant throughout the year, with average temperatures of 30 degrees Celsius and a minimum of 21 degrees celsius.

During the summer, the temperature can be higher.  The tropical climate makes the Great Barrier Reef enjoy plenty of rain, especially during the monsoon period. 

This wet season is also a great reason to add a Daintree tour to your Great Barrier Reef Stay in the wet season.

If you are not from Australia, the weather patterns and terms may be confusing.

North Queensland has a tropical weather pattern that has been consistent over the years.

Generally, the Great Barrier Reef has two seasons: wet and dry.

The rains start to increase in December and are heaviest from January to March, tapering off in April.  From May to November are the dry months and usually have clear blue skies for those seven months.

While you may expect the wet season to be the coolest, it is, in fact, the hottest.

If you are not confused yet, let’s add one more.  You will also hear people refer to the four seasons.  Australia covers different weather zones, and a portion of the country, the most populated, is in a temperate zone.

The seasons are similar to those in Europe and the United States, except they are reversed.

The seasons in the temperate zone are:

  • Winter: June to August
  • Spring: September to November
  • Summer: December to February
  • Autumn: March to May

Tropical Cyclones may form in the summer months over the ocean.

While scientists would disagree, a Cyclone, typhoon and hurricane are all the same.

There are some minor differences, and they develop in different oceans, but the effects are the same.

The cyclone season generally lasts from November to April.

Cairns is in the band for cyclones, but most happen further south.

Local dive operators express that, on average, one week of diving is affected every two years.

Great Barrier Reef Weather Chart from Cairns

Month Max Temp in °C Min Temp in °C Water Temp in °C  Rainfall MM
January 31.6 23.6 29 405
February 31.3 23.7 28 434
March 30.7 23.0 27 424
April 29.4 21.5 26 197
May 27.9 19.5 26 99
June 26.3 17.6 24 49
July 25.9 17.0 24 30
August 26.7 17.5 22 27
September 27.8 18.6 23 35
October 29.4 20.5 26 38
November 30.6 22.2 26 89
December 31.4 23.3 27 175

Excellent Barrier Reef Weather 10-year average

When to visit the Great Barrier Reef

When you look at the monthly average temperatures, you will see that the daytime temperatures stay very comfortable.

You might want to add a sweater or sweatshirt, but more than that is not necessary.

You might need a slightly thicker wet suit in August than in January.

The “wet” season brings warmer water.  The rain patterns are such that more rainfall falls over land than out on the outer reefs.

The distance between most of the reef sites and the coast is significant enough that the runoff from the rain does not affect the visibility on the reef.

The dry season has its advantages as well.  The daytime temperatures are more comfortable.

Great Barrier Reef Weather
Humpback Whale

One significant advantage is migration patterns.  Dwarf Minke Whales, Whale sharks and humpback whales leave the cold winter waters of the Antarctic and move up the Australian coast.

The area north of Cairns is one destination that sees whales every year.