Great Barrier Reef weather by month
Warm all yearJune to October is the dry half; January to March is the warmest.
Warm all year, and June to October is the dry half. Cairns averages 26°C by day in June and July and 32°C in December and January; the Whitsundays run a little cooler, 22°C in July and 30°C in January. Rain is what changes: Cairns drops from 438mm in February to 27mm in August, and the Whitsundays from 329mm in February to 26mm in September. June to October gives you dry days and calm water; January to March is the warmest and greenest, and the quietest. Reef days from Cairns are from $215, and a day sail in the Whitsundays from $199.
Checked on 28 October 2026.
The Great Barrier Reef is 2,300km long, so it is not one forecast. Most people reach it from one of two places: Cairns, for a fast boat to the outer reef, or Airlie Beach, for sailing the Whitsunday islands. Here are both, month by month, together.
Cairns and the Whitsundays, every month
| Month | Cairns day | Cairns rain | Whitsundays day | Whitsundays rain | What it gives you |
|---|---|---|---|---|---|
| January | 32°C | 405mm | 30°C | 281mm | Warm and green, in the heart of the wet |
| February | 31°C | 438mm | 30°C | 329mm | The wettest month, and the quietest |
| March | 31°C | 422mm | 29°C | 271mm | Lush rainforest, the wet easing off |
| April | 29°C | 202mm | 27°C | 192mm | Shoulder season. Rain halves in Cairns |
| May | 28°C | 92mm | 25°C | 122mm | The dry begins. Calmer days |
| June | 26°C | 46mm | 22°C | 81mm | Excellent. Dry and mild |
| July | 26°C | 33mm | 22°C | 65mm | Coolest days and dry air, peak season |
| August | 27°C | 27mm | 23°C | 40mm | Driest in Cairns, 27mm |
| September | 28°C | 34mm | 25°C | 26mm | Driest in the Whitsundays, 26mm |
| October | 30°C | 47mm | 28°C | 38mm | Very good. Warm and still dry |
| November | 31°C | 88mm | 29°C | 90mm | Warming up, the first storms |
| December | 32°C | 194mm | 30°C | 182mm | Hot and lush, with the warmest water of the year |
Bureau of Meteorology long-term monthly averages: Cairns Aero (station 031011, 83 years) and Hamilton Island (station 033255, 17 years) for the Whitsundays.
What the numbers say
- It is warm in every month.The coolest month in Cairns still averages 26°C by day, and nights do not average below 17°C at either end.
- The Whitsundays are cooler by day in winter22°C in July against 26°C in Cairns. Ideal sailing weather.
- The dry comes a little later in the Whitsundays.Cairns is under 50mm a month from June to October; the Whitsundays from August to October, driest in September at 26mm.
- The wet months are the warm months.January to March is the warmest and greenest time, and the quietest on the boats.
Quick answers
- What is the driest month on the Great Barrier Reef?August in Cairns, at 27mm. September in the Whitsundays, at 26mm.
- What is the wettest month?February at both ends: 438mm in Cairns and 329mm in the Whitsundays.
- Is the reef cold in winter?No. July averages 26°C by day in Cairns and 22°C in the Whitsundays, with nights around 17 to 18°C.
- When is the hottest?December and January in Cairns, at 32°C; January to February in the Whitsundays, at 30°C.
So which month?
June to October if you can choose freely: dry, warm and the easiest months on the water. August to October in particular for the Whitsundays. November and December for warmth with the rain still light in the Whitsundays. January to March for the warmest days, the greenest rainforest behind Cairns and the quietest boats. Our best time to visit Cairns and best time to sail the Whitsundays pages go deeper on each end.
The reef days
| Trip | Length | Starts and finishes | From |
|---|---|---|---|
| 1 Day Reef Sailing & Snorkel Tour | 1 day | Cairns / Cairns | $215 |
| 1 Day Snorkel Adventure | 1 day | Cairns / Cairns | $239 |
| 1 Day Luxury Reef Experience | 1 day | Cairns / Cairns | $310 |
| 1 Day Whitsunday - Providence | 1 day | Airlie Beach / Airlie Beach | $199 |
| 3 Day Whitsunday Sail - Solway Voyager | 3 days, 2 nights | Airlie Beach / Airlie Beach | $439 |
From Cairns it is about an hour and a half out to the outer reef, and the snorkel day gives you around five hours in the water across two outer reef sites. On the luxury boat the reef sites are chosen for the day's conditions. Prices update on their own.
1 Day Reef Sailing & Snorkel Tourfrom $2151 dayNon Applicable1 day from Cairns, sailing catamaran, max 20View trip
1 Day Snorkel Adventurefrom $2391 dayNon Applicable1 day from Cairns, two outer reef sitesView trip
1 Day Whitsunday - Providencefrom $1991 day1 day from Airlie Beach, Whitehaven from aboveView trip
3 Day Whitsunday Sail - Solway Voyagerfrom $4393 days, 2 nightsCabin Style3 days sailing the WhitsundaysView tripPeople also ask
- When is the best time to visit Cairns and the Great Barrier Reef?
- When is the best time to sail the Whitsundays?
- Cairns or the Whitsundays for the Great Barrier Reef?
- How do I get to the Great Barrier Reef?
Where this comes from. Temperatures and rainfall are Bureau of Meteorology long-term monthly averages for Cairns Aero (station 031011) and Hamilton Island (station 033255). The reef's length is the Great Barrier Reef Marine Park Authority's published figure. Trip lengths, start points, travel time to the reef, time in the water and prices are each trip's own details as held on its page here, and prices update on their own.