September · Cambodia
Best time to visit Siem Reap in September Weather, crowds & prices
Weather in Siem Reap in September
Average temperature 27°C, 393 mm of rain, about 19 days with 6+ hours of sunshine and 88% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
3.3/10
Ranked #11 of 12 months
- Avg temp
- 27°C
- Rainfall
- 393 mm
- Humidity
- 88%
- Days with 6h+ sun
- 19
- Crowd Density
- Quiet / Uncrowded
- Average Expenses
- $ · Budget Friendly ($)
September in Siem Reap scores 3.3/10 for sightseeing and cultural travel - ranked #11 of 12. Expect around 27°C, 393 mm of rain, and roughly 19 days with 6+ hours of sunshine this month.
Siem Reap is the base for Angkor's temples, with a river town of markets and cafés beside it.
September in Siem Reap: expect compromises
Days in September average 27°C (80°F) and humidity near 88% — front-load outdoor plans before the heat builds and treat the middle of the day as indoor time.
Expect monsoon-level rainfall at 393 mm: only about 19 days with 6+ hours of sunshine across the month, and stretches of heavy rain are normal.
That is 3.3/10 on the same scale — 11th of 12 months, versus 8.4/10 for the best month here.
Pack the lightest breathable clothing you own, a hat, and more water than feels necessary, a proper rain shell rather than an umbrella.
Expect low-season pricing, and crowds are light for this destination.
If your dates are flexible, December is materially better in Siem Reap — 5.1 points higher on the same scale.
Frequently asked
- What is the weather like in Siem Reap in September?
- In September, Siem Reap averages 27°C, 393 mm of rain, and about 19 days with 6+ hours of sunshine. Its climate-comfort score is 3.3/10.
- Is September a good time to visit Siem Reap?
- September earns a 3.3/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Siem Reap in September?
- Expect about 393 mm of rain in September. Average humidity is 88% and there are about 19 days with 6+ hours of sunshine.
Curated in Siem Reap
Tickets & experiences
Things to do in Siem Reap
Siem Reap, Cambodia. Live activities and tours from GetYourGuide, matched to this destination.