Con Dao weather month by month in 2026

Con Dao climate in one paragraph

Con Dao (Côn Đảo) has a tropical monsoon climate with two seasons: dry from December to April, wet from May to October. Mean annual air temperature is 28°C and the sea averages about the same. Around 2,070 mm of rain falls in a year, and close to two thirds of it lands between June and October.

One administrative note, because half the guidebooks are now wrong. Con Dao is no longer a district of Ba Ria-Vung Tau province. Since 1 July 2025 it has been a special zone (đặc khu) under Ho Chi Minh City. The weather did not change; the addresses did.

Phu Quoc is also an island, but it sits in the shallow Gulf of Thailand. Con Dao sits in open South China Sea water, and that changes two things. Wind is stronger here and the monsoons bite harder. And the main island runs southwest to northeast, so each monsoon only ever hits one flank: the lee side stays calm.

Which leads to the one thing worth remembering. Con Dao almost never has bad weather in the literal sense. It has badly chosen beaches.

Three seasons: dry, wet and typhoon

Officially there are two seasons. On the ground it feels like three. Dry is for the beach and the trails. Wet is for turtles and cheap rooms. The typhoon window overlaps the tail of the wet season and plays by different rules: it is not about umbrellas, it is about losing a day to a cancelled flight.

Dry season: December to April

This is the tourist peak. The northeast monsoon pushes dry continental air across the island, monthly rainfall stays at 11-55 mm, and you get 6.5 to 9 hours of sun a day. Humidity holds around 79-81%, which by tropical standards counts as dry.

Air runs 28-32°C by day and 24-26°C at night. In January a light windbreaker earns its place, especially on a boat: out on open water the wind strips the warmth off you fast. The east coast is choppy in these months, since that is where the wind lands, while the west-coast beaches turn to glass.

Wet season: May to October

The southwest monsoon brings humid air in off the Indian Ocean. It rains most days, but not all day. The standard pattern is a clear morning, a 30 to 60 minute downpour around midday, then sun again. By evening everything has dried out.

Rain falls on 15 to 20 days out of 30, but the genuinely wet time is one to three hours a day. If your plan is not "lie on a beach from dawn to dusk", the wet season works fine. It is also the only window for turtles and the only time hotels discount.

Typhoon window: mid-October to December

Direct typhoon hits on Con Dao are rare: southern Vietnam sits off the main storm tracks. But a system passing anywhere across the South China Sea still throws swell and wind at the island. Peak risk is early November.

The fragile part is the logistics. One airport serves the island, Co Ong, and it has no night lighting, so the last departure leaves around 16:00. The aircraft is a turboprop ATR-72, grounded by strong crosswinds and poor visibility. Ferries do not sail in heavy swell, and the port authority makes that call on the morning of the crossing. December 2017 is the example everyone quotes: as Tembin weakened into a depression south of the country, 16 Ho Chi Minh City to Con Dao flights were cancelled in one day and visitors on the island were moved to shelters.

Con Dao weather month by month

These are long-term climate normals. Any given year swings 1-2°C on air temperature and 50-100 mm on rainfall, especially in the wet season. The Day column is the mean daily high, Night is the mean nightly low, not records.

The scary-looking "20 rainy days" in August and September only means rain fell at least once in 24 hours. A fifteen-minute burst at three in the morning counts, and the month goes down as wet. In practice most of the daylight is sun or broken cloud.

Each month up close

January and February

January is the steadiest month of the year: 28°C by day, 24°C at night, sea at 25°C. That is the annual low and it is still comfortable, just not bathwater. The east coast is choppy, so head for Đầm Trầu on the sheltered west side. Hotel rates are at peak with no discounts, so book two months out.

February is the clearest month: 13 mm of rain and a single rainy day. Air 29°C, sea 26°C. Not every dive centre has reopened yet, because the northeast monsoon still keeps the water murky. Lunar New Year (Tết) usually falls in February, and for four or five days the island fills with Vietnamese visitors from Ho Chi Minh City. Room rates jump 30-50%.

March and April

March is the driest month of the year: 11 mm across all 31 days. The northeast monsoon lets go, the sea warms to 27°C, and underwater visibility settles into a workable 10-20 m. If you plan to do a PADI course here, March is a good bet. Walk the park trails early: after eleven they get airless.

April is the hottest month, 32°C by day and 26°C at night, with nine hours of sun. The first showers appear, short and mostly after lunch, adding up to 40 mm. The sea is at its best: 29°C and flat on both sides of the island. Low season has not started, so prices are still high.

May to July

May flips the season. Rainfall jumps from 40 to 210 mm and rain falls on 15 days out of 31. In exchange you get the warmest water of the year at 30°C and the start of nesting on Bãi Cạnh. Hotel rates begin to slide, roughly 20% off peak.

June and July are near-identical: 290-295 mm, 19 rainy days, air 31°C, sea 29-30°C. The west coast churns while the east coast (An Hải, where Six Senses sits) stays calm. Dive boats run in the morning only; afternoon trips get called off for swell. Few visitors, no queues anywhere, hotels down 30%.

August and September

August is the nesting peak. At the height of the season park rangers patrol 18 beaches across the archipelago around the clock. Eggs laid in May and June start hatching at the same time, which makes August the one month where you can realistically catch both halves of the cycle. Rain on 20 days, 300 mm total. Stay on the east coast around An Hải.

September is the most turtle-heavy month of all: nesting is still going and hatchling releases peak. Rainfall 315 mm. The west coast is rough, the east coast reasonably calm. There are almost no visitors and rates bottom out at 35-40% below peak.

October to December

October is the wettest month of the year: 350 mm across 20 days. Dive centres wind down and visibility falls to 5-10 m. If the weather cooperates, though, you get a very quiet and very cheap island. Build in a spare day on the mainland.

November is the typhoon peak, statistically the likeliest month to lose a flight. Rainfall 175 mm over 12 days. From mid-month the monsoon swings to the northeast: the west-coast beaches settle and the east coast starts to churn.

December brings the dry season back with 55 mm of rain over six days, air at 29°C and sea at 26°C. Visitors return and rates climb; for Christmas and New Year, book three months ahead. The typhoon risk fades by late December, though December 2017 is exactly when Tembin came past, so the calendar guarantees nothing.

Best time to visit Con Dao, by goal

The best month depends entirely on why you are going, and the goals fight each other. Turtle season and dive season barely overlap, and the best month for the beach is the worst one for your budget.

Beach and swimming: December to April

Dry season, flat water, sea at 25-29°C. If the beach is the whole point, that is your window. You can still swim in summer, though, as long as you pick the sheltered side: east coast from June to September (An Hải and the Six Senses stretch), west coast from November to March (Đầm Trầu, Ông Đụng).

Diving and snorkelling: March to September

The working dive season runs March to September, and the visibility is best at the front of it: 10-20 m in the dry months, more on a good day. Côn Đảo is one of the better dive destinations in Vietnam, with green turtles, rays, moray eels and reef sharks.

Summer diving happens, but morning only and only when no cyclone is active in the region. From October to February the northeast monsoon raises swell and stirs sediment, visibility falls to 5-10 m, centres close, and sometimes the port keeps the boats in altogether.

Turtles: June to September

Nesting runs from May to October with a June-September peak. Eggs hatch 45-60 days after laying, so releases peak in August and September. The main site is Bãi Cạnh (Bay Canh island), though the park also runs trips to Hon Cau, Hon Tai, Hon Tre Lon and Duong beach. Everything goes through Con Dao National Park; there is no private operator running these.

The format is fixed: a boat from the main port in the afternoon, a ranger briefing, dinner in a basic hut, out onto the beach after sunset around 20:00, back in the morning. Register through the park office at least a week in advance. There is also a short no-overnight option, joining a hatchling release for a token fee of about 50,000 VND (~$2).

Saving money: July to September

Low season takes 30-40% off hotel rates and up to half off the airfare. Ballpark numbers for 2026:

Rate used here: 1 USD ≈ 26,000 VND, checked August 2026. VASCO, the regional arm of Vietnam Airlines, is currently the only carrier on the route: Bamboo Airways dropped Con Dao back in 2024 and suspended scheduled flying altogether in August 2026. Boat fares, unlike airfares, barely move with the season.

Hiking the national park: January to April

Trails are dry, the footing is good, and there are no leeches. The best routes are So Ray (3 km through forest to a viewpoint), the trail down to Ông Đụng beach (4 km each way) and the climb up Núi Thánh Giá, the Cross Mountain, 577 m and 6 km round trip.

In the wet season the trails turn slick and leeches appear in the long grass. Not dangerous, but it takes most of the fun out of it.

Typhoons, cancellations and plan B

Direct typhoon hits on Con Dao are rare. The case everyone remembers, Tembin in December 2017, had weakened to a tropical depression by the time it approached and never made landfall here, yet flights were still cancelled in bulk. A cyclone crossing the South China Sea happens every year, and the swell and wind arrive whether or not the storm does.

What gets cancelled and when

Two things trip up first-time visitors. There are no international flights to Con Dao at all, so you always connect through Ho Chi Minh City or Can Tho. And with the last departure at around 16:00, a same-day connection onto a long-haul out of Saigon is a gamble even in perfect weather.

One naming note: Tran De pier used to be listed under Soc Trang province. After the 2025 reforms it belongs to Can Tho. If an older guide says "ferry from Soc Trang", it means the same jetty.

Plan B when it gets cancelled

1. A spare day on the mainland. Get back to Ho Chi Minh City at least two days before your international departure.
2. The other mode of transport. Flight cancelled? Try a boat, from Vung Tau (bus from Saigon plus about 3.5 hours at sea) or from Trần Đề pier in the Mekong delta. Boat cancelled? Fly.
3. A changeable fare. Vietnam Airlines makes date changes cheaper on mid and higher fare classes; on the cheapest one it is either paid or barred outright. October and November are not the months to save there.
4. Insurance that covers weather cancellations. Most standard policies do, but read the wording rather than assuming.

For forecasts, windy.com shows cyclones 5-7 days out and ventusky.com is easier to read for swell. For a specific departure, the airline app and the boat operators' pages are the only things that settle it on the day.

What to pack, by season

Con Dao is an island with no large shops. Anything you actually need is easier to bring. There are pharmacies in Côn Sơn town, but the range of sunscreen and toiletries is thin.

On reef-safe sunscreen. Dive instructors in Côn Đảo national park may ask you to swap your cream before a dive if it contains oxybenzone or octinoxate. Bring a zinc-based or mineral-based one.

On cash. There are ATMs in town, but power cuts happen in the wet season. Carry a day or two of cash. Exchange rates on the island are close to Saigon rates.

Con Dao, Phu Quoc, Nha Trang and Da Nang

If you are choosing between Vietnamese beach destinations, each has its own window, and they barely overlap.

Here is the part that decides it. In winter, Con Dao and Phu Quoc are the only two Vietnamese destinations where you get into the water without thinking twice: Nha Trang sits at 24-25°C in January and Da Nang at 22-23°C, which many people call cold. Phu Quoc is actually warmer than Con Dao in those months, but it sits in the shallow Gulf of Thailand, with neither the ocean diving nor the nesting beaches. Con Dao also has an unusual typhoon profile for this country. The risk window is short and direct hits are exceptional, while the central coast takes one most years.

Common mistakes

1. Coming in November with no slack in the itinerary. One cancelled flight and the whole plan collapses. Budget two spare days.
2. Booking a room on only one side of the island. In the wet season take the east coast (Six Senses, the An Hải area); in the dry season the west side works too (Đầm Trầu).
3. Planning a dive trip for October to February. Centres are closed and visibility is 5-10 m. The working window is March to September, and the best of it is March to May.
4. Reading "20 rainy days" as "a month of rain". It means rain fell at least once in 24 hours, not that it rained all day.
5. Assuming there is an evening flight off the island. Co Ong has no night lighting, the last aircraft leaves around 16:00, and there are no international arrivals at all, so build the Saigon connection with room to spare.
6. Packing ordinary sunscreen for diving. Reef-safe is not optional here: oxybenzone kills coral and park dive sites genuinely check.
7. Skipping the forecast two days out. Windy shows cyclones 5-7 days ahead and the boat operators update sailing status about 24 hours before departure.

Con Dao weather FAQ

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