Winter
Dec → Feb19 to 20°
nights 15 to 16°
- 7 rainy days · 38 mm
- 5.9 h of sun
- sea 20°
When is the best time to visit Halong Bay?
- Jan19°not recommended
- Feb20°fair
- Mar24°recommended
- Apr26°recommended
- May29°fair
- Jun31°not recommended
- Jul31°not recommended
- Aug31°not recommended
- Sep30°fair
- Oct28°recommended
- Nov26°recommended
- Dec20°fair
RecommendedFairNot recommended· afternoon temperature
The weather in Halong Bay, month by month
The table of records, month by month
| Month | High | Low | Sunshine | Rainfall | Rainy days | Sea | Best |
|---|---|---|---|---|---|---|---|
| January | 19° | 15° | 5.7 h | 51 mm | 10 d | 19° | |
| February | 20° | 16° | 5.6 h | 50 mm | 8 d | 19° | |
| March | 24° | 19° | 5.9 h | 40 mm | 11 d | 21° | ✓ |
| April | 26° | 22° | 8.4 h | 81 mm | 11 d | 26° | ✓ |
| May | 29° | 26° | 9.5 h | 136 mm | 17 d | 29° | |
| June | 31° | 28° | 9 h | 242 mm | 18 d | 32° | |
| July | 31° | 28° | 9 h | 268 mm | 20 d | 32° | |
| August | 31° | 27° | 8.2 h | 419 mm | 25 d | 32° | |
| September | 30° | 26° | 8.5 h | 448 mm | 24 d | 31° | |
| October | 28° | 23° | 8.5 h | 179 mm | 12 d | 28° | ✓ |
| November | 26° | 21° | 8.3 h | 33 mm | 6 d | 25° | ✓ |
| December | 20° | 16° | 6.4 h | 12 mm | 3 d | 21° |
The four seasons in Halong Bay, in figures
What the 2015-2024 records (Sung Sot Cave) show, season by season, to compare at a glance instead of reading twelve rows of a table.
Spring
Mar → May24 to 29°
nights 19 to 26°
- 13 rainy days · 86 mm
- 7.9 h of sun
- sea 25°
Summer
Jun → Aug31°
nights 27 to 28°
- 21 rainy days · 310 mm
- 8.7 h of sun
- sea 32°
Autumn
Sep → Nov26 to 30°
nights 21 to 26°
- 14 rainy days · 220 mm
- 8.4 h of sun
- sea 28°
Book early for March to April and October to November
The timing is right, so it is right for everyone: in these months the best places to stay and the small-group tours go first. Here is where to start.
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What to do in Halong Bay, month by month
| Activity | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hiking | ||||||||||||
| Beach & swimming | ||||||||||||
| Towns & culture | ||||||||||||
| Diving & snorkelling | ||||||||||||
| Events | 2 | 2 | 1 |
EventsTết, Lunar New YearJanuary to FebruaryYen Tu FestivalJanuary to MarchDetails ↓
favourablewith compromisesunfavourable
- Hiking: February, November, December
- Beach & swimming: April, May, June, July, August, September, October, November
- Towns & culture: January, February, March, April, October, November, December
- Diving & snorkelling: April, May, June, July, August, September, October, November
Grid derived from the records (temperature, rainfall, sea), not from an opinion.
What's on in Halong Bay, month by month?
What comes back every year, and when. One of these events fills the hotels and pushes prices up: something to aim for or to avoid, depending on what you want.
- January to FebruaryTết, Lunar New Year big crowds
Vietnamese New Year brings the country to a halt for a week: junks fully booked, transport overloaded and many shops closed.
- January to MarchYen Tu Festival
From Lunar New Year and for three months, pilgrims climb to the Yen Tu monastery, two hours' drive from the bay.
Travelling off-peak
Month by month, in detail
January
Not recommended19°15° at night
- 51 mm · 10 d
- 5.7 h
- sea 19°
Busy, without the crush
February
Fair20°16° at night
- 50 mm · 8 d
- 5.6 h
- sea 19°
Busy, without the crush
March
Recommended24°19° at night
- 40 mm · 11 d
- 5.9 h
- sea 21°
Busy, without the crush
April
Recommended26°22° at night
- 81 mm · 11 d
- 8.4 h
- sea 26°
Busy, without the crush
May
Fair29°26° at night
- 136 mm · 17 d
- 9.5 h
- sea 29°
Low season, lower prices
June
Not recommended31°28° at night
- 242 mm · 18 d
- 9 h
- sea 32°
Low season, lower prices
July
Not recommended31°28° at night
- 268 mm · 20 d
- 9 h
- sea 32°
Low season, lower prices
August
Not recommended31°27° at night
- 419 mm · 25 d
- 8.2 h
- sea 32°
Low season, lower prices
September
Fair30°26° at night
- 448 mm · 24 d
- 8.5 h
- sea 31°
Low season, lower prices
October
Recommended28°23° at night
- 179 mm · 12 d
- 8.5 h
- sea 28°
Busy, without the crush
November
Recommended26°21° at night
- 33 mm · 6 d
- 8.3 h
- sea 25°
Busy, without the crush
December
Fair20°16° at night
- 12 mm · 3 d
- 6.4 h
- sea 21°
Quiet, then the holidays
Read the twelve months in detail
January. Mild, 19 °C in the afternoon and 15 °C early in the morning. Expect 10 days of rain in the month (51 mm). Sunshine gets scarcer (5.7 h a day). Cool sea (19 °C), for the brave. Busy season, without the crush.
February. Mild, 20 °C in the afternoon and 16 °C early in the morning. Expect 8 days of rain in the month (50 mm). Sunshine gets scarcer (5.6 h a day). Cool sea (19 °C), for the brave. Busy season, without the crush.
March. Mild, 24 °C in the afternoon and 19 °C early in the morning. Expect 11 days of rain in the month (40 mm). Sunshine gets scarcer (5.9 h a day). Cool sea (21 °C), for the brave. Busy season, without the crush.
April. 26 °C in the afternoon and 22 °C at night. Expect 11 days of rain in the month (81 mm). Expect 8.4 h of sunshine a day. The sea is at 26 °C, a proper swim. Busy season, without the crush.
May. 29 °C in the afternoon and 26 °C at night. Frequent rain: 136 mm over 17 days. Plenty of sunshine: 9.5 h a day on average. The sea is at 29 °C, a proper swim. Low season: fewer people, lower prices.
June. 31 °C in the afternoon and 28 °C at night. A very wet month, 242 mm of rain over 18 days. Plenty of sunshine: 9 h a day on average. The sea is at 32 °C, a proper swim. Low season: fewer people, lower prices.
July. 31 °C in the afternoon and 28 °C at night. A very wet month, 268 mm of rain over 20 days. Plenty of sunshine: 9 h a day on average. The sea is at 32 °C, a proper swim. Low season: fewer people, lower prices.
August. 31 °C in the afternoon and 27 °C at night. A very wet month, 419 mm of rain over 25 days. Expect 8.2 h of sunshine a day. The sea is at 32 °C, a proper swim. Low season: fewer people, lower prices.
September. 30 °C in the afternoon and 26 °C at night. Frequent rain: 448 mm over 24 days. Expect 8.5 h of sunshine a day. The sea is at 31 °C, a proper swim. Low season: fewer people, lower prices.
October. 28 °C in the afternoon and 23 °C at night. Expect 12 days of rain in the month (179 mm). Expect 8.5 h of sunshine a day. The sea is at 28 °C, a proper swim. Busy season, without the crush.
November. 26 °C in the afternoon and 21 °C at night. Rain stays light: 33 mm over 6 days. Expect 8.3 h of sunshine a day. The sea is at 25 °C: pleasant swimming. Busy season, without the crush.
December. Mild, 20 °C in the afternoon and 16 °C early in the morning. Hardly any rain (12 mm over 3 days). Expect 6.4 h of sunshine a day. Cool sea (21 °C), for the brave. Quiet at the start of the month, then busier as the holidays approach.
Same season, other ideas
Their best time overlaps with this one: worth comparing before you book.
Frequently asked questions
When is the best time to visit Halong Bay?
March to April and October to November: over these months, recorded highs range from 24 to 28 °C, with 10 days of rain a month on average (2015-2024 records, Sung Sot Cave).
Which month should you avoid in Halong Bay?
August: it is the wettest of the months to avoid, with 419 mm over 25 days of rain on average, according to 2015-2024 records at the reference point (Sung Sot Cave).
What is the hottest month in Halong Bay?
June, with 31 °C on average in the afternoon and 28 °C at night. 2015-2024 records (Sung Sot Cave).
What is the coldest month in Halong Bay?
January, with 19 °C at best during the day and 15 °C at night. 2015-2024 records (Sung Sot Cave).
What is the driest month in Halong Bay?
December: 12 mm over 3 days of rain, against 448 mm in September, the wettest month.
Which month has the most sunshine in Halong Bay?
May, with 9.5 h of sunshine a day on average. Note that this counts clear skies, not the length of the day.
When can you swim in Halong Bay?
The water reaches 22 °C or more in April, May, June, July, August, September, October, November (warmest 32 °C in June), measured in 2023-2024 on the nearest coast (Sung Sot Cave).
When is the best time to hike in Halong Bay?
February, November, December: highs between 12 and 29 °C and no more than 9 days of rain a month according to 2015-2024 records (Sung Sot Cave), the safest windows for walking.
When to go diving or snorkelling in Halong Bay?
April, May, June, July, August, September, October, November: the sea is above 25 °C, warm enough to stay in a long time without a thick wetsuit. 2023-2024 records on the nearest coast (Sung Sot Cave).
Plan this trip
📒 The free printable Halong Bay guide: itinerary, map, where to sleep→
🧭 When to visit Vietnam: the country overview→
🗓️ Best time to visit: all our destinations→
Compare with other destinations
Photos: 663highland / CC BY 2.5 (Wikimedia Commons) · NiAksh Prit / Pexels · Saksham Vikram / Pexels · Quang Nguyen Vinh / Pexels