The weather in Interlaken in September is very cold with temperatures between 37°F and 53°F, warm clothes are a must.
You can expect rain for roughly half of the month of September in Interlaken. 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.
You can expect a few days of snow in Interlaken during September. It’s important to get out your snow boots and warm mittens to stay warm while you explore Interlaken.
Our weather forecast can give you a great sense of what weather to expect in Interlaken in September 2025.
If you’re planning to visit Interlaken in the near future, we highly recommend that you review the 14 day weather forecast for Interlaken before you arrive.
