Cairns weather and reef climate in short
Cairns has a wet summer and a drier winter. From January to March it averages more than 400 mm of rain a month, with highs of about 31 °C. From June to September it is the opposite: 26.9 to 45.7 mm and highs of 26 to 28 °C. Airlie Beach follows the same pattern with a little less rain and cooler nights.
The tables are averages, not a forecast for your dates. Use them to choose a month, then read the best time to visit the Great Barrier Reef for stingers and whales. If your dates are fixed, compare Great Barrier Reef tours that can move with the weather.
Cairns weather by month
Averages from the Bureau of Meteorology for the Cairns Aero station.
| Month | Average high (°C) | Average low (°C) | Rain (mm) |
|---|---|---|---|
| January | 31.5 | 23.8 | 404.8 |
| February | 31.3 | 23.8 | 436.1 |
| March | 30.7 | 23.2 | 424.3 |
| April | 29.4 | 21.8 | 201.7 |
| May | 27.7 | 20.0 | 91.6 |
| June | 26.2 | 18.0 | 45.7 |
| July | 25.9 | 17.2 | 33.2 |
| August | 26.7 | 17.4 | 26.9 |
| September | 28.2 | 18.8 | 34.8 |
| October | 29.7 | 20.7 | 47.2 |
| November | 30.8 | 22.4 | 87.9 |
| December | 31.5 | 23.4 | 193.8 |
For most visitors who want warm days with little rain, May to October is the comfortable window in Cairns. December to March is hot, humid and wet.
Our pick: a reef day for any season
Our take: the suit is supplied according to the season, so this reef day works whether you travel in the drier months from May to October or in the hot, wet months.
Hand-picked tours, booked through Viator. Prices are indicative starting prices in Australian dollars (as of October 2026). Tap a tour for live availability and the current price in your currency.
Reef tours that run in all weather
Outer reef trips, island cruises and flights from Cairns, Port Douglas and Airlie Beach, with live prices and availability.
Airlie Beach weather
The nearest weather station for Airlie Beach is Proserpine Airport. It is not a beach measurement, so expect small differences at the coast.
| Month | High (°C) | Low (°C) | Rain (mm) |
|---|---|---|---|
| January | 31.6 | 22.7 | 307.8 |
| February | 31.1 | 22.9 | 351.7 |
| March | 30.3 | 21.8 | 212.0 |
| April | 28.8 | 19.3 | 115.0 |
| May | 26.6 | 15.9 | 64.7 |
| June | 24.8 | 12.9 | 35.9 |
| July | 24.5 | 11.3 | 25.9 |
| August | 25.9 | 11.7 | 24.7 |
| September | 28.5 | 14.5 | 17.8 |
| October | 30.5 | 17.5 | 40.6 |
| November | 31.8 | 19.9 | 79.9 |
| December | 32.2 | 21.8 | 178.5 |
Nights are clearly cooler than in Cairns from May to September, down to 11.3 °C in July. The Whitsundays have their own page: Whitsundays guide.
Water temperature at the outer reef
Rounded monthly values for the outer reef off Cairns.
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 29 | 29 | 29 | 28 | 27 | 25 | 24 | 24 | 24 | 26 | 27 | 28 |
These values describe the outer reef off Cairns. They do not apply to every reef or automatically to the Whitsundays, and they are not air temperatures.
How the seasons feel
Three stretches of the year in Cairns.
December to March
Hot, humid and wet. Highs sit between 30.7 and 31.5 °C, nights stay above 23 °C, and rain of 193.8 to 436.1 mm a month can interrupt boat days.
May to October
Warm days, cooler nights and little rain. Highs run from 25.9 to 29.7 °C and lows from 17.2 to 20.7 °C, with monthly rain between 26.9 and 91.6 mm.
April and November
The shoulder months. April still averages 201.7 mm, while November is drier at 87.9 mm but already hot at 30.8 °C and inside the cyclone season.
What the weather means for your trip
Practical points from the wet and dry months.
Cyclone season
The official season runs from 1 November to 30 April. It is not a closing period, and storms outside it are not ruled out.
Trips can be cancelled
The ride from Cairns to Moore Reef takes about 90 minutes each way and depends on the weather. Boat trips to Green Island can be cancelled by weather too.
Green Island →Hill Inlet
The lookout track at Tongue Point is open around the clock, but check weather and park warnings before you go. It is 1.3 km return and takes about 40 minutes.
Whitehaven Beach →Daintree roads
The Cape Tribulation road can get worse quickly in heavy rain. Mobile coverage is limited, so plan the day before you leave.
Daintree →Stingers
Higher jellyfish risk runs from November to May, and dangerous jellyfish can occur all year. Wear full-body protection.
Sun
The park authority recommends sunscreen and protective clothing for snorkeling at Green Island. Never snorkel alone.
Snorkeling →Farther south, K'gari has its own weather page.
Plan the rest of your trip
Where to stay and how to get there.
Cairns weather: frequently asked questions
What is the weather like in Cairns?
Hot and wet from December to March, with 31 °C highs and more than 400 mm of rain in January to March. Cooler and drier from May to October, with lows down to 17.2 °C in July.
Which is the wettest month in Cairns?
February averages 436.1 mm. The driest is August with 26.9 mm. These are long-term averages, not a forecast.
How warm is the water on the Great Barrier Reef?
At the outer reef off Cairns, rounded values run from 24 °C in July to September up to 29 °C from January to March.
What is the weather like in Airlie Beach?
The nearest station, Proserpine Airport, shows highs from 24.5 °C in July to 32.2 °C in December and rain from 17.8 mm in September to 351.7 mm in February.
When is cyclone season?
Officially 1 November to 30 April. Storms outside those dates are not ruled out.
Is this the official weather website for the reef?
No. This is an independent travel guide, not connected to the Bureau of Meteorology, the Great Barrier Reef Marine Park Authority or any tour operator. Check current forecasts and warnings before you travel.