Con Dao has a dry season from about December to April, with almost no rain from January to March, and a wet season from May to November, peaking in October. It is warm all year, at 28-32°C by day, with a sea of 25-30°C. But on an island reached by boat and small planes, the wind matters as much as the rain: the seas are calmest from March to September, the diving season, while the north-east monsoon brings rough water from about November to February. Sea turtles nest from April to October, peaking from June to September.
Con Dao is a remote archipelago in the South China Sea off Vietnam's southern coast, most of it a national and marine park. Since July 2025, it has been a special zone of Ho Chi Minh City.
Con Dao weather at a glance
The table gives official long-run averages for Con Dao from the Vietnam Institute for Building Science and Technology, as published in Wikipedia's climate table. Sea temperatures are satellite averages from Sea Temperature.
| Month | High | Low | Rain | Rain days | Sunshine (h/month) | Sea |
|---|---|---|---|---|---|---|
| January | 27.9°C | 24.1°C | 13 mm | 2 | 206 | 24.9°C |
| February | 28.6°C | 24.1°C | 13 mm | 1 | 222 | 25.7°C |
| March | 30.1°C | 24.7°C | 11 mm | 2 | 264 | 26.6°C |
| April | 31.6°C | 25.5°C | 39 mm | 5 | 268 | 28.1°C |
| May | 31.9°C | 25.6°C | 210 mm | 15 | 223 | 29.7°C |
| June | 31°C | 25.4°C | 289 mm | 19 | 172 | 29.6°C |
| July | 30.7°C | 25.2°C | 297 mm | 19 | 182 | 29.4°C |
| August | 30.5°C | 25.3°C | 298 mm | 20 | 183 | 29°C |
| September | 30.4°C | 25°C | 316 mm | 20 | 159 | 28.8°C |
| October | 30.1°C | 24.9°C | 351 mm | 20 | 162 | 28.9°C |
| November | 29.4°C | 25.3°C | 175 mm | 12 | 161 | 28.2°C |
| December | 28.2°C | 24.7°C | 53 mm | 6 | 162 | 26.6°C |
The year totals about 2,060 mm of rain. Notice how steady the temperature is: nights barely move from 24-26°C all year. The seasons are set by rain and wind.
Dry season, December to April: sun, then calm
From January to March, the three months together bring only about 37 mm of rain, and the sun shines for 206 to 264 hours a month. December still sees some showers as the rains end. The catch in early winter is the wind: the north-east monsoon, from about November to February, makes the sea rough, reduces visibility for divers and can close the harbour, so boat trips and ferries are less reliable.
March to May is the sweet spot. The rain has gone, the wind drops, the sea warms from about 27°C to nearly 30°C, and April is the sunniest month of the year. It is the best time for beaches, snorkelling and diving.
Wet season, May to November: rain, turtles and calm seas
About 95% of the year's rain falls from May to November, at 175 to 350 mm a month over 12 to 20 rain days, with October the wettest. The rain usually comes in showers and afternoon storms. Surprisingly for a wet season, the seas are often calm through the summer, and Con Dao Dive Center treats March to September as its peak season.
It is also turtle season. Green turtles nest on Con Dao's beaches from about April to October, peaking from June to September, according to Thanh Nien, which reported more than 2,000 nesting visits a year and about 150,000 hatchlings released. Con Dao National Park runs overnight trips to Bay Canh island to watch nesting and hatchlings, listed at about 2.15 to 5.1 million VND, and the dive centre runs its own trips. Visits are led by park rangers, and flash photography is not allowed.
Getting there in every season
Flights. Vietjet and Vietnam Airlines fly to Con Dao, mostly from Ho Chi Minh City, with a few flights from Hanoi and Can Tho. The small aircraft on some routes can be delayed or cancelled in bad weather.
Ferries. High-speed ferries run from Vung Tau, about 4 hours, and from Tran De in Can Tho, about 2 to 2.5 hours. They stop when the port authority bans sailing because of strong winds and big waves, most often from November to February and when storms pass, and operators offer free date changes or refunds. Our ferry prices guide has the fares, and our Vung Tau weather guide covers the mainland side of the crossing.
Whenever you go, leave a spare day before an onward flight or connection.
Typhoons: rare
In southern Vietnam, typhoons generally come between mid-October and late December, peaking in early November, and most dissipate over the sea before reaching land, although they can bring big waves. They are rarely the problem on Con Dao; the monsoon winds are.
What the weather means for your trip
Choosing the month. March to May for beaches and diving; June to September for turtles, with rain; December to February for dry but windy days.
Planning. Our Con Dao guide covers the prison history, the beaches and where to stay, and our Phu Quoc vs Con Dao comparison helps you choose between the two southern islands. For Phu Quoc's calendar, see our Phu Quoc weather guide.
Limitations
The table uses official long-run averages for Con Dao's weather station as reproduced on Wikipedia; the source does not state the averaging period or rain-day threshold. Diving and turtle season dates come from the national park, the dive centre and the press, and they vary slightly between sources. Sea conditions change quickly with the wind.
Workaround: check the sea and wind forecast before you book boat trips, confirm ferry sailings the evening before, and build a spare day into your plans.