Siem Reap Weather in September 2026: what to expect (4.3/10)

The month in detail

What to expect in September

September falls in the wet season in Siem Reap. Showers are often brief but intense. With 91.0% of rainy days, always have indoor alternatives planned.

September ranks 9 out of 12 months in Siem Reap. Compared to August: 10 pts more rainy days, −0.8h of sun per day.

This month's conditions

What it's like in September

UV index

8 · high

sunscreen and hat advised

Feels like

oppressive heat

24°

Daylight

12.1h of daylight

Air quality

good

AQI 22

Compare

Is September the right month?

The best month in Siem Reap is January (6.1/10), 1.8 pt higher than September.

See January →See all 12 months →

Context

Our verdict

Siem Reap is the base for visiting Angkor Wat , the world's largest religious complex (400 km²). January is my favourite month (6.9/10): 22-31°C, 7% rain, this is the dry season, acceptable humidity.

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.

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Stay

Hotels & rentals · Siem Reap

Expedia →

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Activities

Tours, tickets, experiences

See ↓

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Flights

Multi-airline comparator

Kiwi →

🎟️ Activities & tours · Siem Reap

GetYourGuide selection · free cancellation

See all →

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 · Cambodia

🗣️LanguageKhmer

💶CurrencyRiel cambodgien (៛)

🚗DrivingRight-hand

🛡️Safety ⓘSafe · 2/5

💰Cost of living ⓘCheap · 2/5

🌡️ Climate

🌍Climate typeTropical

📈Climate trend ⓘStable

🔥Hottest monthMarch · 34°C

❄️Coolest monthDecember · 30°C

🌧️Rainiest month ⓘSeptember · 91%

🏝️ 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

San SalvadorEl Salvador

Nearby

Koh ChangThailand219 km

PattayaThailand326 km

Phu QuocVietnam348 km

Ho Chi Minh CityVietnam413 km

Other top picks

Cape VerdeCape Verde5.3

SalCape Verde5.6

Marsa AlamEgypt5.8

Sharm el-SheikhEgypt5.8

HurghadaEgypt5.9

← August October →

🗺️ See all 754 destinations on the map

Location

Where is Siem Reap ?

Global position + regional geographic context.

🌍 World

🔍 Geographic context

Cambodia

Tropical climate with a 6.1 → 4.3 gap between best and worst month. 10 years of ERA5 data to choose by project.

13.36°N · 103.86°E

Questions

Frequently asked questions

What is the best time to visit Siem Reap?

January is the best month with 31.0°C highs, 22.0°C lows, 8.2h of sunshine and 7.0% rainy days.

How many hours of sunshine does Siem Reap get in January?

Siem Reap averages 8.2 sunshine hours per day in January. It is the sunniest month with a climate score of 6.0/10.

What is the rainiest month in Siem Reap?

May is the most unfavourable month with May has the lowest climate score of the year and the lowest climate score of the year.

What are the temperatures at night in Siem Reap in January?

In January, overnight lows reach 22.0°C, while afternoon highs average 31.0°C.

Is Siem Reap good in winter?

In winter (December-February), Siem Reap scores 5.7/10 on average — Decent period conditions for cultural visits.. The best month overall remains January with a score of 6.0/10.

When should you avoid Siem Reap?

May is the most difficult month to visit Siem Reap, with May has the lowest climate score of the year. Climate conditions are at their lowest of the year during this period.

Do you need sun protection in Siem Reap in September?

The average UV index reaches 8 in September in Siem Reap (high), with about 12.1h of daylight. Sunscreen and hat advised.