Interlaken weather in September
“Mild and bright — an underrated time to visit.”
Roughly 15 rainy days across the month, on average.
September in Interlaken brings mild alpine conditions with daytime temperatures averaging 20.2°C (68°F) and cooler nights at 13.1°C (55°F). Expect around 142mm of precipitation spread across roughly 15 rainy days, though you'll still enjoy about 9.5 hours of sunshine daily. The weather is pleasantly cool without the summer crowds, making it ideal for outdoor exploration.
This is shoulder season in Interlaken, offering a peaceful atmosphere as families return to school and peak tourists depart. The surrounding meadows remain vibrant green, wildflowers still dot the landscape, and the Jungfrau region is fully accessible. You'll find fewer queues at attractions and more authentic local experiences in restaurants and villages.
For 2026 travel planning, September strikes an excellent balance between reliable weather and lower prices compared to July and August. Pack layers since temperatures can fluctuate, and bring waterproof gear for afternoon showers. This month suits hikers, photographers, and anyone seeking the Swiss Alps without summer intensity.
What to pack for Interlaken in September
Layer up for September's cool alpine climate with breathable fabrics that handle variable conditions. Mornings and evenings can feel chilly, while midday sun warms things up. Rain is frequent but usually brief, so packable protection is essential.
- Lightweight merino wool base layers
- Fleece-lined rain jacket
- Long-sleeve linen shirt
- Comfortable hiking trousers
- Waterproof hiking boots
What to pack for Interlaken in September
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Where to stay in Interlaken
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Compare hotels on Booking.com→Things worth doing
Mountain hiking on Jungfrau trails, paragliding over alpine valleys, lake kayaking on Brienzersee, scenic train rides through valleys.
Other places with a similar climate right now
Interlaken in September — FAQ
Q01Is September a good time to visit Interlaken?
Is September a good time to visit Interlaken?
It is a fair time to visit — expect variable conditions and plan flexibility. In September, Interlaken averages a high of 20°C (68°F) and a low of 13°C (55°F), with 148mm of rainfall across roughly 15 rainy days.
Q02What is the average temperature in Interlaken in September?
What is the average temperature in Interlaken in September?
The average high temperature in Interlaken during September is 20°C (68°F), with an average low of 13°C (55°F). These figures are averaged from ten years of daily records (2015–2024, Open-Meteo Archive).
Q03How many rainy days does Interlaken have in September?
How many rainy days does Interlaken have in September?
Interlaken averages approximately 15 rainy days in September, with a total monthly rainfall of about 148mm. This is based on daily precipitation records where days with 1mm or more of rain are counted as rainy days.
Q04What should I pack for Interlaken in September?
What should I pack for Interlaken in September?
For Interlaken in September, pack layered clothing for changing temperatures, a compact umbrella or waterproof jacket, sunscreen and sunglasses, comfortable walking shoes. These recommendations are based on the ten-year weather averages for this specific month.
Q05How crowded is Interlaken in September?
How crowded is Interlaken in September?
Tourist crowds in Interlaken during September are typically moderate — shoulder season, a sweet spot between crowds and weather. Consider this when planning accommodation — prices track crowd levels closely.