Cairns Seasonal Information
The weather in Cairns is tropical. This makes it perfect to enjoy the beautiful Great Barrier Reef all year round!
There are only two seasons – the wet season from December to April and the dry season from May to November, although we can have early starting or late finishing seasons.
The dry season (May-November) is the most popular time of year to visit Cairns due to its mild weather and sunny days.
Christmas, school holidays and Chinese New Year (late Jan-mid Feb) are also busy, so if you are planning on visiting during those times, make sure you book your tours ahead.
Dry season: May-November
- The dry season’s average temperature ranges from 18°C (night time) – 26°C (64 – 79°F).
- The days can be humid, but usually with a cool ocean breeze.
- Average winds from April – August approx 15-20 knots (east south-easterly)
- Average water temperature 24°C (75°F).
- Humpback whale watching season July – September.
Wet season: December-April
- The wet season’s average temperature ranges from 23°C (night time or after lots of rain) – 31°C (73 – 88°F).
- During this time of year humidity can be high
- The majority of rainfalls occur between January and March, although it is still warm and humid when it rains
- The wet season brings the possibility of tropical storms between December and March
- Average water temperature is 28°C (82°F).
The ocean temperature ranges from 24 – 28°C so it is suitable for swimming all year round.
We have a beautiful waterfront in Cairns, but there is no sand. Instead we have a lagoon that is perfect for swimming all year round.
About 10 minutes drive North of Cairns is the start of what we call the “Northern Beaches”. They are a series of small towns with lovely beaches. Due to the Great Barrier Reef, they don’t have waves big enough for surfing, but they are beautiful and great for a swim. If you are swimming at the beaches, it is best to swim at patrolled beaches in between the flags. Those that are patrolled all year round include Palm Cove, Trinity Beach and Port Douglas.
The water in freshwater creeks and waterholes is a lot cooler than the ocean, perfect for a dip on a hot day.
Make sure you heed any warning signs and do not swim where it is not safe to do so.
Wind conditions & visibility
Everybody wants a perfectly calm, sunny day on the reef and we want you to experience that! But reality is, some days it rains and some days its windy. You can still have a great day on the reef despite those things.
It can often be raining in Cairns, but sunny on the reef, due to clouds hanging around the mountains behind Cairns. And if it is raining, don’t worry, you’re going to get wet anyway!
Water visibility (how clearly you can see under water) is affected by particles floating in the water. They can be caused by a few things, but are mostly wind-related – currents, choppy seas, storm conditions.
Unfortunately visibility changes on a daily basis, so it is mostly impossible to predict.
Wind conditions, however, can be predicted 3 days in advance by the Bureau of Meteorology, but this is not often helpful to people. If travelling in peak season, tours are often booked out more than 3 days in advance, plus most people have limited time in Cairns.
Another thing wind can effect is your tummy. If you’re not sure whether you get seasick, it is always a good idea to take tablets as precaution, it is not nice spending the day feeling sick. A lot of people are surprised they get seasick, even in mild conditions, and trust me, you don’t want to be one of those people! Ginger tablets are a gentle natural option and most boats have complimentary ginger tablets on board. But the most effective tablets are the ones you get from the pharmacy. They should be taken at least 30 minutes prior to departure, once you feel sick, it is too late to take them.
Wind conditions of:
- 5 – 10 knots = perfectly glassy water
- 10 – 15 knots = light winds
- 15 – 20 knots = light-average winds
- 20 – 25 knots = moderate winds.
- 25 – 30 knots = strong winds
- 35 knots = very strong winds (rare occurrence)
In the rare occurrence of reef boats being cancelled due to bad weather conditions, a full refund is given to customers.
Due to the mountain range behind Cairns (which is part of the Great Dividing Range), it is rare for cyclones to reach Cairns. The last cyclone to make landfall in Cairns was Cyclone Willis in 1927.
However, Cairns has been affected by Cyclonic activity hundreds of kilometres away, notable the Innisfail Cyclones of 2006 and 2011. It caused strong winds and tidal flooding.
The Reef Sharks that inhabit the Great Barrier Reef are relatively harmless and if you go out on a day trip to the reef you probably won’t encounter one. If you do see one, it will most likely be a black or white tipped small reef shark. They are very shy and do not pose a threat to humans.
In Far North Queensland we have two different types of crocodiles: freshwater and saltwater.
Freshwater crocodiles are shy and tend to avoid humans. They grow up to 2 meters and have a pointed nose, similar to an alligator. They have never killed anyone and are considered non-threatening to humans.
Saltwater crocodiles are the large ones that can grow up to 6 metres long. They are vicious and territorial, although attacks are rare as they don’t like to co-inhabit with humans. Saltwater crocodiles do pose a real threat, do not swim if there is a warning sign, it is there for a reason!
You will not encounter any crocodiles out on the reef, they like to live near the shore as that is where they breed and sunbake. It is rare to find them at our swimming beaches and those that have ventured to one have been re-located by rangers.
Although they are called saltwater crocodiles, they can also live in freshwater, especially estuaries. So do not swim where rivers meet the ocean. They do not climb up waterfalls, so waterholes and rivers at a higher elevation can be safe to swim at, just check with a local if your not sure.
Marine stingers and jellyfish
Jellyfish season is October to April. There are two types of jellyfish – box jellyfish and Irukandji jellyfish, commonly known as ‘stingers’. Both types like to live near the coast.
Box jellyfish are never seen on the reef and Irukandji are rarely seen but during jellyfish season tour operators recommend you wear a Lycra suit just in case. A Lycra (also known as stinger suit) is a light thin wetsuit that all tour operators carry on board. Some boats have them included for free and some you have to pay to hire them (around $5 – 10).
During jellyfish season most swimming beaches put out stinger nets making a safe enclosure to swim in. However, the nets are not 100% safe and occasionally the lifeguards may shut the beach.