Halong Bay weather – Catherine Cruise
Halong Bay has a tropical monsoon climate with two main seasons: the hot and rainy season from May to October and the cool and dry season from November to April. During the hot season, temperatures can reach up to 35°C with high humidity and frequent rain showers, while during the cool season temperatures average around 20°C with less rainfall. Overall, the best time to visit Halong Bay is from October to April when the weather is pleasant and the visibility is better for viewing the scenic landscape.

Halong bay in September
Halong bay in September 2023 (Photo: Orchid Cruises)
Halong bay in Fall & Spring (September to November and March to May)
Lowest temperature: 13ºC
Highest temperature: 32ºC
Humidity: 79%-85%

Deciding on the best time to visit will depend on your personal preferences. As many people prefer the cool, dry weather of Spring and Fall, the peak visiting times tend to be from March to April and September to October. During these months, you can expect more sunny days, a cooler breeze and calmer weather. A minor shower is to be expected occasionally, but they rarely last long enough to disrupt visitors’ plans.

Halong bay in Summer (May-September)

Lowest temperature: 21ºC
Highest temperature: 38ºC
Humidity: 81.5%

Summer lasts from around May to September, and in this time, the air is hot and humid. This warmer weather helps create beautiful sunsets, viewable at times when there is no rain or fog. While the promise of summer heat can be tempting, the months of July to September are also the wettest, so visitors should check weather forecasts for signs of severe weather. Temperature high for these months is 38°C.

Halong bay in Winter (November to March)
Lowest temperature: 10ºC
Highest temperature: 19ºC
Humidity: 79.2%

Winter lasts from around November to March. These months are the coldest with temperatures dropping down to 10°C – 20°C on average with a low of 16°C. This is also the dry season, not a lot of rainfall is to be expected.

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