What is the weather like in Vientiane in September?

Expect temperatures between 24°C and 30°C with 77% average rain probability and about 8 hours of sunshine daily.

What is the weather like in Vientiane in September?

Vientiane in September scores 53/100 based on 30 years of climate data. Good option with minor considerations.

Who should visit Vientiane in September?

September in Vientiane is ideal for: Business travelers.

Vientiane Weather in September | 30-Year Forecast

Avg High

30°C

Hottest around day 2

Avg Low

24°C

Coolest around day 25

Rainy Days

30days

77% avg rain chance

Sunshine

8hrs/day

Autumn season

Essential Travel Info for Vientiane

🗓️ Best Time to Visit 📖 Travel Guide 🍴 Food Guide

Currency

LAK

₭ Lao kip

Language

Lao

Driving

Right side

Connect

Most hotels, restaurants, cafes, bars et...

Safety

High Safety

GPI: 1.809

Travel Intelligence

Exclusive flight analytics & health data for Vientiane

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Airport-to-Airport Logistics

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Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Low Traffic

22/ 100

Traffic Index

Quieter airport

Peak Daily Arrivals

slots per day

Peak

Dec

Low

Jun

Monthly Traffic Distribution

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Traffic Level

Low Season

Key Connections

Kunming Changshui (KMG)

Bangkok Suvarnabhumi (BKK)

Pakse (PKZ)

Nong Khang (NEU)

Seoul Incheon (ICN)

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 Laos.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 younger than 60 years old traveling to Laos. Unvaccinated travelers 60 years and older may get vaccinated before traveling to Laos.

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 Laos 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 areasPresent in the southern part of the country in the provinces of Attapeu, Champasak, Khammouane, Salavan, Savannakhet, and SekongRare cases in the northern part of the countryNone in the cities of Luang Prabang and Vientiane (the capital)Drug resistanceChloroquine and mefloquineSpeciesP. vivax(55%)P. falciparum(45%)P. knowlesi,6P. malariae,andP. ovale(rare)Recommended chemoprophylaxisIn the provinces of Attapeu, Champasak, Khammouane, Salavan, Savannakhet, and Sekong: Atovaquone-proguanil, doxycycline, tafenoquine2Northern part of the country: No chemoprophylaxis recommended (insect bite precautions and mosquito avoidance only)4Updated April 23, 2025See footnotes

+4 more

Source: CDC Travelers' Health

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Is September a Good Time to Visit Vientiane?

👌Good option with minor considerations(53/100)

Short Answer

Vientiane during September means embracing the rain (77%, 9mm typical). Some activities may be affected, but the lush landscapes and fewer tourists can be rewarding.

Decision Factors

Oppressive heat and humidity

29.8°C with 86% humidity - challenging conditions

High rainfall period

77% rain probability, 9.3mm average

Vaccinations required

Yellow Fever

Feels significantly hotter than 29.8°C

Heat index: 39°C due to 86% humidity

Health precautions needed

Be aware of: Leptospirosis, Melioidosis, Schistosomiasis

Plenty of sunshine

8h of sunshine daily

Good For

💼
Business travelers
Climate-controlled meetings unaffected by weather

Who Should Avoid

👨‍👩‍👧‍👦
Families with children
39°C heat index dangerous for children
👴
Elderly travelers
Heat index of 39°C poses health risks
🥾
Outdoor enthusiasts
77% rain probability disrupts outdoor activities
📸
Photographers
81% cloud cover limits natural light opportunities

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,Vientiane in September averages 30°C with 77% precipitation probability."

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

Frequently Asked Questions: Vientiane in September

What are the temperatures in Vientiane in September?

Daytime highs average 30°C, nights drop to 24°C. Temperatures remain fairly consistent.

How many rainy days in Vientiane in September?

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

What to wear in Vientiane in September?

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

Is September peak season in Vientiane?

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

Vientiane Weather in September

Vientiane September Weather Calendar