January
Heron Island's bird life is very active. This month is the peak breeding season for sea birds, particularly Black Noddies, Mutton Birds and Reef Herons. Pisonia grandis have sticky seeds falling from the trees. Female Turtles are laying eggs on the beach and turtle hatchlings can be seen making their way to the sea.
Average rainfall - 196mm
Average temperature - min 23.6C max 29.8C
Average water temperature - min 26.5C max 30.5C

February
Wedge tailed Shearwater Mutton Bird chicks hatching - Island birdlife remains active on Heron Island. Female Turtles are still laying eggs and hatchlings continue to emerge from the nests.
Average rainfall - 136mm
Average temperature - min 23.5C max 29.5C
Average water temperature - min 26.5C max 30.5C

March
Migratory types of birds, such as the Ruddy Turn-stone and Eastern Golden Plover depart Heron Island. Some show breeding plumage as they return to their Arctic nesting grounds. Birds still nesting, include the Buffbanded Rail and the Black Noddy. Female turtles are at the end of the nesting season.
Average rainfall - 155.99mm
Average temperature - min 23.3C max 29.0C
Average water temperature - min 25.0C max 28.0C

April
Most of the Noddies depart Heron Island. Young Wedge-tail Shearwater birds (Puffinus pacificus) leave their burrows. Adult Shearwaters leave the Island.
Average rainfall - 79.0mm
Average temperature - min 21.6C max 27.3C
Average water temperature - min 23.2C max 27.0C

May
The last of the turtle hatchlings can be seen emerging from their nests. Young Wedge-tailed  Shearwaters are still learning to fly and should leave Heron Island by the end of the month.
Average rainfall - 109.7mm
Average temperature - min 19.4C max 24.4C
Average water temperature - min 19.5C max 23.0C

June
Humpback Whales northern migration begins and they are often seen passing through waters around Heron Island. An average Humpback weighs 40 tonnes and measures 16 metres.
Average rainfall - 105mm
Average temperature - min 16.2C max 21.8C
Average water temperature - min 19.0C max 22.0C

August
A month warming up to spring, more general activity on the reef and on Heron Island. Towards the end of the month the Black Noddies begin returning. Good Humpback Whale sightings.
Average rainfall - 46.2mm
Average temperature - min 14.6C max 26.0C
Average water temperature - min 20.0C max 23.0C

September
Humpback Whales are active. Humpbacks are well known for their breeching habits. Black Noddies are now returning to the Island will commence nesting. Turtle mating may be seen. Northern Hemisphere migratory birds, such as Ruddy Turnstones and Eastern Golden Plovers arrive back on Heron Island.
Average rainfall - 26.1mm
Average temperature - min 15.8C max 27.0C
Average water temperature - min 20.0C max 24.0C

October
Whales now heading south to the Antarctic with their calves. Black Noddies nesting. Wedge-tailed Shearwaters returning to Heron Island to nest. Resident Silver Eyes nesting. Turtle mating may be observed.
Average rainfall - 43.5mm
Average temperature - min 16.7C max 29.0C
Average water temperature - min 20.0C max 26.0C

November
Turtle egg laying begins. Wedge-tailed Shearwaters can be seen digging and repairing nesting burrows. It is the start of their breeding season. Black Noddies' eggs can be seen in the nest. N.B. The annual synchronised mass spawning of corals usually occurs during this month. Spawning synchronises with the lunar month and dates vary, usually 3 - 4 days after the full moon. If corals do not spawn in this month, they will in December.
Average rainfall - 54.1mm
Average temperature - min 18.5C max 29.0C
Average water temperature - min 22.0C max 28.5C

December
Bird life is extremely active. Numerous Black Noddy chicks can be seen. Wedge-tail Shearwaters are laying eggs in their burrows. Turtles are laying eggs and hatchlings emerging from the sand. Coral spawning may occur.
Average rainfall - 55.8mm
Average temperature - min 22.0C max 29.4C
Average water temperature - min 25.0C max 29.0C