What is the weather like in Halong Bay in September?

Expect temperatures between 25°C and 30°C with 59% average rain probability and about 8 hours of sunshine daily.

What is the weather like in Halong Bay in September?

Halong Bay in September scores 51/100 based on 30 years of climate data. Good option with minor considerations.

Who should visit Halong Bay in September?

September in Halong Bay is ideal for: Business travelers.

Halong Bay Weather in September | 30-Year Forecast

Avg High

30°C

Hottest around day 5

Avg Low

25°C

Coolest around day 26

Rainy Days

30days

59% avg rain chance

Sunshine

8hrs/day

Autumn season

Sea Temperature in September

Coastal Waters(Ocean)

30.5°C

Monthly Average

Water Feel

🌴Tropical

Perfect for swimming and water sports

Swim Rating

✅Excellent for swimming

Based on average sea surface temperature

Body of Water

Coastal Waters

Ocean

Halong Bay coastline

Essential Travel Info for Halong Bay

🗓️ Best Time to Visit 📖 Travel Guide 🍴 Food Guide

Currency

VND

₫ Vietnamese đồng

Language

Vietnamese

Driving

Right side

Safety

High Safety

GPI: 1.786

Travel Intelligence

Exclusive flight analytics & health data for Halong Bay

Smart Flight Estimator

Airport-to-Airport Logistics

unlock smart flight estimates

Add your home location in settings to see airport details.

Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Remote

10/ 100

Traffic Index

Off the beaten path

Peak Daily Arrivals

slots per day

Peak

Jul

Low

Dec

Monthly Traffic Distribution

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Traffic Level

Low Season

Key Connections

Ho Chi Minh City Tan Son Nhat (SGN)

Da Nang (DAD)

Nha Trang Cam Ranh (CXR)

Seoul Incheon (ICN)

Dalat Lien Khuong (DLI)

Health & Safety Advisory

CDC travel health recommendations

10 Recommendations

COVID-19

All eligible travelers should be up to date with their COVID-19 vaccines. Please seeYour COVID-19 Vaccinationfor more information.

Chikungunya

All travelers should take steps to prevent mosquito bites. Chikungunya vaccination is generally not recommended. Travelers who wish to consider vaccination can visit “What to consider before traveling” on thechikungunya vaccinespage to learn more.

Hepatitis A

Recommended for unvaccinated travelers one year old or older going to Vietnam.Infants 6 to 11 months old should also be vaccinated against Hepatitis A. The dose does not count toward the routine 2-dose series.Travelers allergic to a vaccine component should receive a single dose of immune globulin, which provides effective protection for up to 2 months depending on dosage given.Unvaccinated travelers who are over 40 years old, are immunocompromised, or have chronic medical conditions planning to depart to a risk area in less than 2 weeks should get the initial dose of vaccine and at the same appointment receive immune globulin.

Hepatitis B

Recommended for unvaccinated travelers of all ages traveling to Vietnam.

Japanese Encephalitis

Recommended for travelers whoAre moving to an area with Japanese encephalitis to liveSpend long periods of time, such as a month or more, in areas with Japanese encephalitisFrequently travel to areas with Japanese encephalitisConsider vaccination for travelersSpending less than a month in areas with Japanese encephalitis but will be doing activities that increase risk of infection, such as visiting rural areas, hiking or camping, or staying in places without air conditioning, screens, or bed netsGoing to areas with Japanese encephalitis who are uncertain of their activities or how long they will be thereNot recommended for travelers planning short-term travel to urban areas or travel to areas with no clear Japanese encephalitis season.

Malaria

CDC recommends that travelers going to certain areas of Vietnam take prescription medicine to prevent malaria. Depending on the medicine you take, you will need to start taking this medicine multiple days before your trip, as well as during and after your trip. Talk to your doctor about which malaria medication you should take.Transmission areasRural areas only; rare cases in the Mekong and Red River DeltasNone in the cities of Da Nang, Hai Phong, Hanoi, Ho Chi Minh City (Saigon), Nha Trang, and Quy NhonDrug resistanceChloroquine and mefloquineSpeciesP. vivax(55%)P. falciparum(44%)P. knowlesi,6P. malariae, andP. ovale(rare)Recommended chemoprophylaxisProvinces of Bình Dương, Bình Phước, Đắk Lắk, Đắk Nông, Gia Lai, Khánh Hòa, Kon Tum, Lâm Đồng, Ninh Thuận, Tây Ninh: Atovaquone-proguanil, doxycycline, tafenoquine2All other areas with malaria transmission (except Mekong and Red River Deltas): Atovaquone-proguanil, doxycycline, mefloquine, tafenoquine2Mekong and Red River Deltas: No chemoprophylaxis recommended (insect bite precautions and mosquito avoidance only)4Updated April 23, 2025See footnotes

+4 more

Source: CDC Travelers' Health

View Complete Health Guide

Is September a Good Time to Visit Halong Bay?

👌Good option with minor considerations(51/100)

Short Answer

September brings storm season risk to Halong Bay. While typical weather is 30°C with 59% rain, plan for potential disruptions and secure cancellation-friendly bookings.

Decision Factors

Typhoon season active

Western Pacific zone - expect potential typhoon activity

Oppressive heat and humidity

29.8°C with 84% humidity - challenging conditions

Vaccinations required

Yellow Fever

Feels significantly hotter than 29.8°C

Heat index: 38°C due to 84% humidity

Warm tropical seas

30.5°C sea temperature - Hot Soup

Frequent rainfall expected

59% chance of rain - pack waterproofs

Good For

💼
Business travelers
Climate-controlled meetings unaffected by weather

Who Should Avoid

💰
Budget travelers
Peak season means premium prices everywhere
👴
Elderly travelers
Heat index of 38°C poses health risks
🥾
Outdoor enthusiasts
59% rain probability disrupts outdoor activities
💑
Honeymoon couples
Wedding score only 69/100 - better months available

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,Halong Bay in September averages 30°C with 59% precipitation probability."

📊 Source: 30YearWeather.com🛰️ Data: NASA POWER (1991-2021)View Methodology →

Frequently Asked Questions: Halong Bay in September

What are the temperatures in Halong Bay in September?

Daytime highs average 30°C, nights drop to 25°C. Temperatures remain fairly consistent.

How many rainy days in Halong Bay in September?

Expect around 30 days with measurable rainfall. Definitely pack rain gear.

What to wear in Halong Bay in September?

Light, breathable fabrics. Don't forget sunglasses and a hat.

Is September peak season in Halong Bay?

This is off-peak season. Expect lower prices and fewer crowds.

Halong Bay Weather in September