The weather in Sumatera Utara 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 Sumatera Utara. 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 Sumatera Utara in September 2025.
If you’re planning to visit Sumatera Utara in the near future, we highly recommend that you review the 14 day weather forecast for Sumatera Utara before you arrive.