Click on a day for an hourly weather forecast
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.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 32° / 21° | 1 | 30 | 0 | 24 mm | Good | Siem Reap in January |
| February | 34° / 23° | 1 | 27 | 0 | 31 mm | Ok | Siem Reap in February |
| March | 36° / 26° | 4 | 27 | 0 | 99 mm | Ok | Siem Reap in March |
| April | 36° / 27° | 10 | 20 | 0 | 216 mm | Bad | Siem Reap in April |
| May | 35° / 27° | 13 | 18 | 0 | 298 mm | Bad | Siem Reap in May |
| June | 33° / 26° | 17 | 13 | 0 | 367 mm | Ok | Siem Reap in June |
| July | 32° / 25° | 21 | 10 | 0 | 426 mm | Ok | Siem Reap in July |
| August | 32° / 25° | 20 | 11 | 0 | 444 mm | Ok | Siem Reap in August |
| September | 31° / 25° | 22 | 8 | 0 | 575 mm | Ok | Siem Reap in September |
| October | 31° / 24° | 16 | 15 | 0 | 487 mm | Ok | Siem Reap in October |
| November | 31° / 23° | 6 | 24 | 0 | 151 mm | Good | Siem Reap in November |
| December | 31° / 22° | 1 | 30 | 0 | 32 mm | Good | Siem Reap in December |