The weather in Sumatra in September is very hot. The average temperatures are between 23°C and 33°C, drinking water regularly is advisable.
You can expect rain for roughly half of the month of September in Sumatra. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Sumatra in September 2025.
If you’re planning to visit Sumatra in the near future, we highly recommend that you review the 14 day weather forecast for Sumatra before you arrive.
Temperatures
33° / 23°
Rainy Days
13
Snowy Days
0
Dry Days
17
Rainfall
229
mm
Sun Hours
11.5
Hrs
