The weather in Siem Reap in September is very hot. The average temperatures are between 25°C and 31°C, drinking water regularly is advisable.
There’s going to be many days of rain during the month of September in Siem Reap.
Siem Reap should expect an average of 15 to 22 days of rain, so be sure to bring along a waterproof jacket to stay dry this month!
Our weather forecast can give you a great sense of what weather to expect in Siem Reap in September 2025.
If you’re planning to visit Siem Reap in the near future, we highly recommend that you review the 14 day weather forecast for Siem Reap before you arrive.
Temperatures
31° / 25°
Rainy Days
22
Snowy Days
0
Dry Days
8
Rainfall
575
mm
Sun Hours
10.2
Hrs
