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.

If you are not from Australia, the weather patterns and terms can be a little confusing.

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

Generally, the Great Barrier Reef as having two seasons, a wet season and a dry season.

The rains start to increase in December, are at their heaviest from January to March, tapering off in April. May to November is the dry months.

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

If you are not totally 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 weather patterns here are similar as you will find 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

This would help explain why the wet months is also the hottest, it in the summer if there were four seasons.

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

While scientist 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 the majority of them happen further north.

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

Great Barrier Reef Weather 10-year average

When to visit the Great Barrier Reef

If you look at the monthly average temperatures, you will see that the day time temperatures stay very comfortable.

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

You might need a slightly thicker wet suit in August than in January, but no need to bring out a dry suit.

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

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

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

Great Barrier Reef Weather
Humpback Whale

One major advantage is migration patterns. Dwarf Minke Whales,

Whale sharks and, to a lesser extend, humpback whales leave the cold winter waters of the Antarctic and move up the Australian coast.

The area north of Cairns is one of the destinations that see these marine animals every year.