An independent guide to Ha Long Bay, Lan Ha and Bai Tu Long
Plan the dates
Weather and sea conditions, month by month
Ha Long's weather has two seasons on paper and four in practice: a cool, misty late winter, a warm and clearer spring, a hot and stormy summer, and a dry, mild autumn. This page shows what each month brings and what happens when a storm closes the port.
The month chart
Our reading of the climate data and storm notices cited below: filled = generally good, half = workable with trade-offs, empty = poor or higher risk.
The chart is a summary, not a forecast. A clear January day happens, and so does a storm in October. Use it to see where the trade-offs lie, then check the forecast and any port notices in the week you travel.
Sources: weather2travel — Ha Long Bay monthly climate averages (CRU and Met Office data); UK Foreign Office — Vietnam safety and security · last checked .
Month by month
| Month | Max / min °C | Sea °C | Rain mm | Sun h/day | What to expect |
|---|---|---|---|---|---|
| January | 20 / 13 | 19 | 27 | 3 | Cool, grey, often misty; calm seas |
| February | 20 / 14 | 19 | 31 | 2 | Coolest month on average; drizzle and mist; Tet crowds |
| March | 23 / 17 | 20 | 43 | 3 | Mild; mist lifts slowly; water still cold |
| April | 27 / 21 | 23 | 91 | 4 | Warmer and clearer; a comfortable month |
| May | 31 / 24 | 27 | 168 | 6 | Hot; swimming starts; first storms possible |
| June | 32 / 25 | 29 | 244 | 6 | Hot and humid; thunderstorms; storm notices begin |
| July | 32 / 26 | 29 | 267 | 7 | Peak heat; afternoon storms; typhoon risk |
| August | 32 / 25 | 30 | 312 | 6 | Wettest month; highest cancellation risk |
| September | 31 / 24 | 29 | 206 | 6 | Still stormy; major typhoons in 2024 and 2025 |
| October | 29 / 21 | 28 | 119 | 6 | Drier and clearer; sea still warm |
| November | 25 / 17 | 25 | 55 | 5 | Dry and mild; a comfortable month |
| December | 22 / 14 | 22 | 24 | 5 | Driest month; cooler; clear days and some mist |
Averages are long-term figures processed from climate datasets; rainy days are counted as days with any rain. The Vietnam National Authority of Tourism gives an annual mean of about 23°C for Ha Long city, with June the warmest month and February the coolest.
Sources: weather2travel — Ha Long Bay monthly climate averages (CRU and Met Office data); Vietnam National Authority of Tourism — Ha Long city overview and climate · last checked .
Mist, heat and the in-between months
December to March. North-east winds bring cool, damp air. The sea is calm, which suits sleeping aboard, but visibility is often only a few kilometres and sunshine averages two to three hours a day. The bay looks soft and monochrome rather than blue and green. Bring a warm layer for the deck.
April to June. Air and sea warm quickly; April is often the most comfortable month of the year on the water. From May the heat builds and afternoon thunderstorms appear.
July to September. Hot, humid and wet, with south-west winds. Rain often falls in heavy bursts with clear spells between, so a wet forecast does not mean a wasted day. The serious risk is storms.
October and November. Rainfall drops sharply, the sea stays warm into October, and the light is clear. Storms remain possible in October.
Sources: weather2travel — Ha Long Bay monthly climate averages (CRU and Met Office data); Vietnam National Authority of Tourism — Ha Long city overview and climate · last checked .
Typhoon season and what happens to your trip
The UK Foreign Office says the tropical cyclone season normally runs from May to November, though storms can happen at other times. When a storm threatens, Quang Ninh's waterway authority stops issuing departure permits to tourist boats. Recent examples show how this works:
- June 2025, Storm Wutip: overnight permits suspended for Ha Long Bay, and all tourist boats ordered to bring passengers back to the mainland before 6 pm.
- July 2025, Typhoon Wipha: permits halted for all Ha Long Bay tourist boats on 20 July; the bay and Tuan Chau port reopened on the morning of 23 July after inspections.
- September 2025, Typhoon Ragasa: vessel permits suspended from 10 am on 24 September until the final storm bulletin; 60 overnight boats with 1,594 passengers were brought back to dock.
- September 2024, Typhoon Yagi: landfall in Quang Ninh and Hai Phong on 7 September, with winds of 133 to 148 km/h near the centre.
Lan Ha Bay falls under Hai Phong's civil defence authorities, which issue their own notices. A boat can be cleared to leave Ha Long and still be unable to enter Lan Ha, or the reverse.
Sources: UK Foreign Office — Vietnam safety and security; Ha Long Bay Management Board — permits suspended for Storm Wutip, June 2025; Tuoi Tre News — tourist boats barred from departing ahead of Typhoon Wipha; Voice of Vietnam — Ha Long Bay reopens after Typhoon Wipha; Vietnam News Agency — Quang Ninh halts vessel permits as Typhoon Ragasa nears; Viet Nam News — Typhoon Yagi makes landfall in Quảng Ninh and Hải Phòng (2024); Hai Phong newspaper — sea restrictions lifted after Storm Kajiki (August 2025) · last checked .
Sudden thunderstorms
Typhoons give days of warning. Summer thunderstorms do not. On 19 July 2025 a sightseeing boat on route 2, between Sung Sot and Ti Top, capsized in a sudden thunderstorm in mid-afternoon. Of the 49 people aboard, 39 died. Investigators reported that the boat had been built taller than the standards allowed and lacked an automatic emergency alert device, and experts said the six-hourly weather updates then in use were not enough for sudden storms.
For travellers the practical lessons are simple: on a summer afternoon, watch the sky, keep your life jacket within reach, and take a crew's decision to cut a route short or stay at anchor seriously.
Sources: Tuoi Tre News — loopholes found after the July 2025 capsizing; People's Army Newspaper — tourist boat capsizes in Ha Long Bay (20 July 2025) · last checked .
Planning around the weather
- Between June and October, leave a spare day in your itinerary after the bay, not before your flight home.
- Read the cancellation terms before you pay: what is refunded, or moved, if the authorities stop departures.
- Prefer trips that can switch to a shorter route or a day trip if overnight permits are suspended.
- In winter, pack warm layers and accept that views will often be misty; the sea is calm.
- Check the national weather service forecast and local news on the day before, not just a phone app.
Common questions
Questions readers ask
Which months suit a visit to Ha Long Bay?
There is no single answer. April to June and October to November combine warm weather, clearer air and lower storm risk. December to March is calm but cool and misty.
Do cruises get cancelled in typhoon season?
Yes. When a storm approaches, Quang Ninh stops issuing departure permits to tourist boats, and overnight trips are suspended first. Closures in 2025 lasted from part of a day to about three days.
Is it too cold to visit Ha Long Bay in winter?
Not too cold to visit: daytime highs are around 20°C in January and February. It is too cold for most people to swim, and mist often limits views.
When is the rainiest month?
August, with about 312 mm on average, followed by July and June.
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