What is the weather like in Phnom Penh in September?

Expect temperatures between 25°C and 31°C with 81% average rain probability and about 8 hours of sunshine daily.

What is the weather like in Phnom Penh in September?

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

Who should visit Phnom Penh in September?

September in Phnom Penh is ideal for: Business travelers.

Phnom Penh Weather in September | 30-Year Forecast

Avg High

31°C

Hottest around day 1

Avg Low

25°C

Coolest around day 20

Rainy Days

30days

81% avg rain chance

Sunshine

8hrs/day

Autumn season

Essential Travel Info for Phnom Penh

🗓️ Best Time to Visit 📖 Travel Guide 🍴 Food Guide

Currency

KHR

៛ Cambodian riel

Language

Khmer

Driving

Right side

Connect

Cheap SIM cards from US$2 for GSM phones...

Safety

High Safety

GPI: 1.882

Travel Intelligence

Exclusive flight analytics & health data for Phnom Penh

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Airport-to-Airport Logistics

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Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Low Traffic

24/ 100

Traffic Index

Quieter airport

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

Guangzhou Baiyun (CAN)

Bangkok Suvarnabhumi (BKK)

Kuala Lumpur (KUL)

Bangkok Don Mueang (DMK)

Taipei Taiwan Taoyuan (TPE)

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 Cambodia.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 Cambodia. Unvaccinated travelers 60 years and older may get vaccinated before traveling to Cambodia.

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 Cambodia 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 areasPrimarily isolated to pockets in rural and forested areasRare cases in non-forested areasNo (or negligible) malaria transmission in the cities of Phnom Penh (the capital) and Siem ReapNo (or negligible) malaria transmission at the main temple complex at Angkor WatDrug resistanceChloroquine and mefloquineSpeciesP. vivax(95%)P. falciparum(5%)P. malariaeandP. knowlesi6(rare)Recommended chemoprophylaxisRural and forested areas: Atovaquone-proguanil, doxycycline, primaquine5, tafenoquine2Areas with rare cases: 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 Phnom Penh?

👌Good option with minor considerations(53/100)

Short Answer

September isn't Phnom Penh's most comfortable season - 31°C and sticky 84% humidity will challenge most visitors. Consider air-conditioned tours and plan for afternoon breaks.

Decision Factors

Oppressive heat and humidity

31°C with 84% humidity - challenging conditions

High rainfall period

81% rain probability, 7.6mm average

Vaccinations required

Yellow Fever

Feels significantly hotter than 31°C

Heat index: 42°C due to 84% humidity

Health precautions needed

Be aware of: Leptospirosis, Melioidosis, Schistosomiasis

Plenty of sunshine

8.1h of sunshine daily

Good For

💼
Business travelers
Climate-controlled meetings unaffected by weather

Who Should Avoid

👨‍👩‍👧‍👦
Families with children
42°C heat index dangerous for children
👴
Elderly travelers
Heat index of 42°C poses health risks
🥾
Outdoor enthusiasts
81% rain probability disrupts outdoor activities
📸
Photographers
90% cloud cover limits natural light opportunities

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,Phnom Penh in September averages 31°C with 81% precipitation probability."

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

Frequently Asked Questions: Phnom Penh in September

What are the temperatures in Phnom Penh in September?

Daytime highs average 31°C, nights drop to 25°C. Temperatures remain fairly consistent.

How many rainy days in Phnom Penh in September?

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

What to wear in Phnom Penh in September?

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

Is September peak season in Phnom Penh?

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

Phnom Penh Weather in September

Phnom Penh September Weather Calendar