Halong Bay Weather In May

Last updated on
March 29, 2024

Tourists often do research in advance to make sure they pick the right month to visit a foreign location. Because Halong Bay – a site of Natural World Heritage – is one of the most well-known tourist destinations in Vietnam, it is normal when you see many tourists posting questions about the weather of this place.

One question that has not been properly answered is during which month, the weather is better to visit Halong, April or May?

Let’s take a look at the following article to find the information you need to make your decision.

halong bay view

In short:

  • High chance of rain so don’t forget to pack your raincoat; summer is in full swing
  • Fewer international visitors are expected in May as it’s the beginning of off-peak season
  • There will be a surge of domestic visitors at the beginning of the month due to the long holiday

Is May a good time to travel to Halong Bay?

Comparing the weather between two months in different seasons is often easier, as the differences are more apparent. However, when it comes to April and May in Halong Bay, even a small distinction can significantly impact your decision.

May is considered one of the optimal months to visit Halong Bay due to its favorable weather conditions. The region has a tropical climate characterized by hot and humid summers and cool winters. During May, which falls within the summer season, temperatures are warm and pleasant. The climate is generally inviting for outdoor activities and exploration.


While April serves as a transitional month from spring to summer, May signals the official beginning of summer and brings with it a higher average temperature of approximately 27.5°C. This temperature is about 5°C hotter compared to April and is comparable to the temperatures experienced in June. Consequently, May boasts one of the hottest year-round temperatures in Halong Bay. 

However, it’s important to note that this heat is not brutal, and passengers on cruises will not feel the need to stay indoors for the majority of their trip. 

Additionally, the number of sunlight hours increases from 4 hours per day to 7-8 hours per day as the days become longer over a month.

Rainfall & Humidity

With infrequent rain, April is considered a dry month of the year in Halong while it is slightly likely to experience summer storms in May.

There are about 14 days of rain in May with an average rainfall of 192mm. The average humidity level is 75%. May is characterized by minimal rainfall in Ha Long Bay, ensuring fewer interruptions during your outdoor activities. However, it’s always advisable to be prepared for the possibility of occasional showers.

Sea Temperature

The average sea temperature in May is 27°C, about 3°C higher than in April, making it more suitable for swimming and diving activities

Summary of Halong Bay weather in May

TemperatureAverage: 28°C
Lowest: 25°C
Highest: 32°C
Sunshine hours/day8 hours
Average precipitation192mm
Number of rainy days14
Humidity level75%
Sea temperature27°C

Pros and Cons of traveling to Halong Bay in May


  • May boasts warm weather, plentiful sunshine, and lower rainfall, creating ideal conditions for participating in water sports or simply lying under the sun on the sundeck.
  • May falls within the off-peak season for travel, enabling you to take advantage of discounted cruise rates and experience a less crowded Halong Bay, with fewer tourists.
  • Daylight hours are longer compared to previous months, affording you additional time to partake in a variety of captivating activities.


  • Occasionally, May’s weather conditions may bring about storms or heavy rainfall. While such occurrences are relatively infrequent, there is a possibility of cruise cancellations due to inclement weather.
  • At the start of May, Halong Bay may experience higher levels of crowding due to Labor Day celebrations and the Halong Carnival.

Tips for traveling to Halong Bay in May

Booking Tips:

  • Take advantage of May’s off-peak season to secure more affordable cruise prices compared to other months of the year.
  • If you prefer a less crowded and quieter experience, May is an ideal time to visit as the bay is less touristy during this period.
  • Keep in mind that there is a higher likelihood of cruise cancellations in May due to unforeseen inclement weather conditions. Stay informed about weather forecasts and be prepared for potential disruptions.

Packing Tips:

  • As May is one of the hottest months in Halong Bay, pack lightweight clothing such as t-shirts, polo shirts, singlets, and shorts to stay comfortable in the warm temperatures.
  • Essential items to bring include sunglasses, sunscreen, a swimsuit, and a hat to protect yourself from the intense sunlight.
  • Be prepared for possible rain showers by packing a raincoat or other waterproof gear to stay dry during any unexpected rainfall.

Recommended activities to take part in May

Both April and May in Halong Bay provide suitable weather for engaging in water-based activities and adventures, making them quite similar in terms of weather conditions. Popular activities such as hiking, canoeing, cave visiting, swimming, and squid fishing can be enjoyed during both months. However, May tends to be warmer, resulting in increased perspiration. On the other hand, the sea temperature in May makes it a better choice for diving.

To explore the marvelous underwater world of Halong, it’s recommended to have essential equipment like snorkels, masks, exposure suits, etc. You have the option to bring your gear or rent it on-site.

Cruising is always a popular choice, and there are various cruise packages available to choose from. A typical 3-day-2-night package often includes additional activities like squid fishing, visits to floating villages, and bike riding.

Given the similarities between April and May, the choice ultimately depends on your personal preference. If you don’t mind the summer heat, both months are suitable for your visit. If you have a particular interest in attending the carnival festival, it would be wise to select the month when the event takes place. Generally, October is considered the best month in terms of weather, but April and May come close behind.