Interlaken Weather in September
September in Interlaken brings moderate temperatures around 14°C (57°F) during the day, dropping to 4°C (39°F) at night, with quite a bit of rainfall expected, averaging around 162 mm (6.4 in) for the month.
Rainfall in Interlaken in September
Climate statistics over the past 30 years suggest around 15 days of rain, with 162 mm (6.4 in) average for the month. The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.
Temperature in Interlaken in September
Expect highs of 14°C (57°F) in Interlaken in September, with nights dropping to around 4°C (39°F). Conditions are often most pleasant around the middle of the day. Nights drop to 4°C (39°F). Cold nights like these are actually great for sleeping well, as long as you have a warm enough duvet.
Sunshine in Interlaken in September
The month experiences a moderate amount of sunlight, with 149 hours of sunshine. This provides a nice balance between sunshine and clouds.If you favor pleasant temperatures and minimal rainfall, September is one of the best months to visit Interlaken.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Switzerland, check out our Interlaken's climate page.
Interlaken Temperature in September
Min Temperature
4°C (39°F)
Max Temperature
14°C (57°F)
Chance of Rain
49%
Precipitation
162 mm (6.4 in)
Rainy days
15 days
Humidity
80%
Sunshine
149 hours
Percentage Sunshine
52%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Interlaken typically drop from around 21°C (70°F) at the start of September to approximately 17°C (63°F) by the end. Nights are cool, with lows typically ranging from 7°C (45°F) to 10°C (50°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Interlaken in September
Browse day-by-day weather records for Interlaken spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Interlaken historical weather extremes in September
Based on weather observations in Interlaken between 1976 and 2025, these are the recorded extremes during September.
- The warmest day in September was on September 14, 1987, with a maximum of 31°C (88°F).
- Interlaken experienced its chilliest September day on September 19, 1977, reaching only 3°C (37°F).
- Nighttime temperatures dropped to -11°C (12°F) on September 18, 1977, marking the coldest September night on record.
- Peak precipitation in September occurred on September 19, 2021, when 46 mm (1.8 in) of precipitation was measured.
Best Places in Switzerland in September
Find out more about the weather in Switzerland and which places have the best travel conditions in this month. See all of Switzerland in September →
perfect weather
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What to Wear in Interlaken in September
The weather can be unpredictable in September, so pack clothes you can easily mix and match. You could bring jeans, other long pants, and a few t-shirts. A light jacket or light sweater will be pleasant for the cooler moments. Also bring a poncho, it will rain a lot! Waterproof everything you can. Sunglasses could come in handy during the sunnier parts of your trip.What To Do in Interlaken in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Switzerland, check out our Interlaken's climate page.
Temperature Rainfall Sunshine Humidity
See the full Interlaken climate overview or explore weather in Switzerland.
