Halong Bay Weather: What to Expect Throughout the Year

Halong Bay weather is very typical of a tropical climate, with 2 main seasons dominating throughout the year. From April to September the weather tends to be hot and humid with sporadic summer storms, and from October through until March it is mainly dry and cool. To give you a more detailed insight into the Halong Bay weather, this article will go through all four seasons.

Tours and cruises operate all year round in Halong Bay, so whichever time you prefer to visit will just depend on your own tastes. Let’s have a look in detail at the typical Halong Bay weather throughout the year.

Halong Bay Weather by Season

1. Spring

Months: March, April, May

Overall weather: Warm, clear skies

Weather breakdown:

  • Temperature: Average Spring temperatures are 23.7 degrees, with March bringing the coolest temperatures at 20 degrees, and May the highest at 28.
  • Rainfall: March and April are generally very dry with infrequent rains, while May often represents the beginning of the summer storms, and averages 14 days of rain in the month.
  • Sunlight: Each month brings a respective 8 hours of daily direct sunshine, which is the highest levels of the year.
  • Humidity: Expect moderate humidity in the summer months, with averages of 75-80% (this tends to get higher as the stormy summer months approach).

Tourist season: end of high season, with a few public holidays


  • Halong Bay celebrates many festivals throughout the year, all of which are a wonderful way to experience traditional Halong culture. One of the most famous festivals here is the Halong Carnival, which features singing, dancing, parades, costumes, fireworks, and loads of performances put on by the locals. This usually takes place at the end of April or start of May.
  • These ‘spring’ months are perhaps the best times to visit Halong Bay, because you avoid the peak season, but the weather is still pretty good and there’s tons to see and do.

2. Summer

Months: June, July, August

Overall weather: Hot, humid, frequent storms

Weather breakdown:

  • Temperature: Average summer temperatures are 31 degrees Celsius, which is significantly higher than the annual average of 23.7. In fact, it’s not unusual for summer temperatures to shoot up in excess of 35 degrees.
  • Rainfall: This is considered to be Halong Bay’s rainy season; these three months account for 80-85% of Halong’s entire annual rainfall. August tends to be the wettest month, with an average of 14-16 days experiencing more than 175mm of rain.
  • Sunlight: The summer months bring an average of 7 hours of full sunlight each day (August is the lowest of the year at 6 hours).
  • Humidity: Due to the stormy weather and frequent rains, the summer months are the most humid of the year with highs of 90%.

Tourist season: low season


  • If you don’t mind the hot weather, the summer months are a great time to visit as they are considered to be ‘low season’, so you can often avail of significant discounts from some cruises.
  • If you are visiting during the summer months, be aware of the possibilities of storms. The Southwest monsoon comes along in summer, which has been known to bring wind speeds reaching up to 160 km/hr. Keep an eye on the forecast before making a booking, and make sure to ask your cruise company about it before you set off.

3. Autumn

Months: September, October, November

Overall weather: Warm, sporadic storms

Weather breakdown:

  • Temperature: Averages of 25 (September is the warmest at 28, and November the coolest at 22).
  • Rainfall: Coming out of the stormy summer months, Autumn generally brings a break in the clouds. Although September is still quite shower-prone, with 14 days experiencing rainfall, October and November are considerably drier.
  • Sunlight: A seasonal average of 7.25 hours of direct sunlight each day (November is the highest with 8 full hours)
  • Humidity: Humidity levels drop significantly as we move away from summer and shift into winter mode, with averages around 75%.

Tourist season: end of low season/lead up to high season


  • Squid fishing season in Halong Bay runs from April until December. At the beginning of the season the squid will be smallest, so the biggest catches usually come between September and December. If you visit Halong Bay during this time of year, you’ll have the chance to get in on the action with one of the squid fishing workshops offered by many of the cruises.

4. Winter

Months: December, January, February

Overall weather: Cooler than usual- but still relatively warm, clear skies

Weather breakdown:

  • Temperature: Average of 18 degrees, with the warmest in December at 19 degrees and the coolest in January at 17.
  • Rainfall: The winter months are the driest months of the year, which is one of the main reasons this is considered to be “high season”. Rain at this time of year is minimal (4-40mm).
  • Sunlight: Average of 7.3 hours of direct sunlight. December is the highest with 8 full hours.
  • Humidity: Humidity levels are at their lowest in the winter months thanks to the infrequent rains and plentiful sunshine. Averages linger from 65-70%.

Tourist season: high season


  • If you prefer a cooler, more temperate climate, visit during the winter months.
  • Halong Bay’s peak season falls in December and January, mostly due to the favourable Halong Bay weather at this time of year. Peak season can result in a very crowded bay, and high levels of cruise bookings.
  • January is the best time of the year to enjoy swimming in Halong Bay thanks to the high average sea temperatures (29 degrees Celsius).


Here is an infographic for Halong Bay weather:

halong bay weather infographic

Need some further info about the Halong Bay weather? Check out our month by month guide.

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