What to expect in Siem Reap in September
September is usually the wrong time for Siem Reap: 31° / 24°. Consider January · February instead.
Siem Reap weather in September
Typical conditions in Siem Reap during September, based on long-run climate normals rather than any single year. Treat it as a planning guide, not a forecast.
| Average high | 31°C 88°F |
|---|---|
| Average low | 24°C 75°F |
| Rainfall | Wet 85/100 |
| Total rainfall | 305 mm12.0 in |
| Daylight | 12 h 13 min |
| How it feels | Hot — midday shade matters |
Average highs sit around 31°C with lows near 24°C. Expect a fair amount of rain, so plan indoor backups.
Crowds & demand
Crowd levels are Low for Siem Reap — plenty of space at the main sights.
Prices & value
This month counts as low season: some of the best deals of the year.
What to pack
Lightweight, breathable clothes, strong sun protection and a refillable bottle — highs near 31°C make midday heat the main constraint. Add a compact rain shell and shoes you do not mind soaking; this is one of the wetter months.
What it costs
This is one of the cheaper months to visit Siem Reap. Flights and accommodation sit near their yearly floor, and you can usually book late without being punished for it. Compared with the most expensive month of the year, you are looking at roughly 69% less.
Who this month suits
- Anyone travelling on a budget
- People who would rather have space than perfect conditions
- Visitors who want to catch a festival
Events & what’s on
Look out for Angkor Wat Equinox Sunrise, Pchum Ben while you’re there.
- Angkor Wat Equinox Sunrise — The sun rises directly behind Angkor Wat's central tower on the spring and autumn equinoxes.
- Pchum Ben — Families offer food to deceased ancestors at pagodas during this fifteen-day ancestor festival.
Siem Reap in September compared with nearby months
If your dates are flexible by a few weeks, this is what shifting them actually buys you.
| Month | Temp | Crowds | Price | Score |
|---|---|---|---|---|
| July | 32° / 24° | Low | $ | 63 |
| August | 32° / 24° | Low | $ | 63 |
| September · This month | 31° / 24° | Low | $ | 66 |
| October | 30° / 23° | Low | $ | 64 |
| November | 30° / 21° | Moderate | $$ | 55 |
These months score higher for Siem Reap on the same blend of weather, crowds and price. Same destination, better odds.
Or go somewhere else in September
If the destination is negotiable but the month is not, these places are at their best in September.
Figures are climate normals and modelled estimates — a planning guide, not a forecast. We separate fact, estimate and recommendation. Updated October 2026
