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Halong Bay, Vietnam · Tropical

Halong Bay in September: go or not?

Mixed period. Halong Bay in September: 4.7/10.

📅 Updated August 2026 🛰️ ERA5 · 10 years 📍 20.91°N · 107.18°E
⚡ This month's verdict
Why not
Halong Bay · September
4.7
26–30°
Temperature
72%
Rain
6h
Sun
🌴 Tropical☀️ High UV🌧️ Monsoon season
Photo : Vincent Guth via Unsplash
The month in detail

What to expect in September

September falls in the wet season in Halong Bay. Showers are often brief but intense. With 72.0% of rainy days, always have indoor alternatives planned.

September ranks 9 out of 12 months in Halong Bay. Compared to August: 15 pts fewer rainy days, +1.2h of sun per day.

This month's conditions

What it's like in September

UV index
7 · high
sunscreen and hat advised
Feels like
oppressive heat
25°
Sea
30°C
warm, ideal
Daylight
12.1h of daylight
Air quality
fair
AQI 51
Compare

Is September the right month?

The best month in Halong Bay is November (8.3/10), 3.6 pts higher than September.

See November →See all 12 months →
Context

Our verdict

The Halong Bay (UNESCO 1994) is the postcard image of Vietnam: 1969 emerging karst limestone islands over 1500 km² in the Gulf of Tonkin. November is my favourite month (8.6/10): 20-26°C, 25% rain, clear skies after the monsoon, mild temperatures.

Read Gilles' full review →

Book

Plan your trip

Hotels at their lowest outside peak season, highest on comfortable months. Shoulder seasons offer a good price/climate compromise.

🏨
Stay
Hotels & rentals · Halong Bay
Expedia →
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Activities
Tours, tickets, experiences
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Flights
Multi-airline comparator
Kiwi →

🎟️ Activities & tours · Halong Bay

GetYourGuide selection · free cancellation

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Affiliate link · GetYourGuide
Practical info

What you need to know before you go

Three angles: the country (language, currency, safety, budget), the year-round climate, and the specifics of a tropical stay.

Country · Vietnam

🗣️LanguageVietnamese
💶CurrencyVietnamese Dong (₫)
🚗DrivingRight-hand
🛡️Safety ⓘSafe · 2/5
💰Cost of living ⓘVery cheap · 1/5

🌡️ Climate

🌍Climate typeTropical
📈Climate trend ⓘStable
🔥Hottest monthJune · 31°C
❄️Coolest monthJanuary · 20°C
🌧️Rainiest month ⓘAugust · 87%

🏝️ Tropical stay

🌞Dry season ⓘMay → Sep
🌧️Wet season ⓘDec → Mar
🌀Cyclones ⓘSeason Nov-Apr
Explore

Other destinations in September

If September doesn't convince you for this destination, compare with others.

Similar climate
MacauChinaHong KongChinaOrlandoUSAHanoiVietnamKaohsiungTaiwan
Nearby
Ninh BinhVietnam146 kmSa PaVietnam380 kmHueVietnam497 kmLaosLaos538 km
Other top picks
Cape VerdeCape Verde5.3SalCape Verde5.6Marsa AlamEgypt5.8Sharm el-SheikhEgypt5.8HurghadaEgypt5.9
← AugustOctober →
🗺️ See all 754 destinations on the map
Location

Where is Halong Bay ?

Global position + regional geographic context.

🌍 World
🔍 Geographic context
Vietnam
Tropical climate with a 8.3 → 4.4 gap between best and worst month. 10 years of ERA5 data to choose by project.
20.91°N · 107.18°E
Questions

Frequently asked questions

What is the best time to visit Halong Bay?
November is the best month with 26.0°C highs, 20.0°C lows, 7.0h of sunshine and 25.0% rainy days. The months of November & October offer comparable conditions.
How many hours of sunshine does Halong Bay get in November?
Halong Bay averages 7.0 sunshine hours per day in November. It is the sunniest month with a climate score of 7.8/10.
What is the rainiest month in Halong Bay?
August is the most unfavourable month with August has the lowest climate score of the year and the lowest climate score of the year.
What are the temperatures at night in Halong Bay in November?
In November, overnight lows reach 20.0°C, while afternoon highs average 26.0°C.
Is Halong Bay good in winter?
In winter (December-February), Halong Bay scores 7.3/10 on average — Decent period conditions for cultural visits.. The best month overall remains November with a score of 7.8/10.
When should you avoid Halong Bay?
August is the most difficult month to visit Halong Bay, with August has the lowest climate score of the year. Climate conditions are at their lowest of the year during this period.
Can you swim in Halong Bay in September?
In September, the sea averages 30°C in Halong Bay: warm, ideal. Ideal conditions for swimming and snorkeling.
Do you need sun protection in Halong Bay in September?
The average UV index reaches 7 in September in Halong Bay (high), with about 12.1h of daylight. Sunscreen and hat advised.