🇨🇭 Weather in Interlaken in September
This is what the weather in Interlaken (Bernese Oberland, Switzerland) was like in September in 2017–2026.
Key facts at a glance
Avg. daytime high
13.8 °C
10.4 °C – 17.6 °C
Avg. night-time low
4.8 °C
1.9 °C – 7.2 °C
Avg. rain days in period
15.2
51 % of days · ≥ 1.0 mm
Avg. precipitation in period
123 mm
42.5 mm – 207 mm
Avg. sunshine per day
n/a
Sunshine duration is not available from this data source.
Avg. sea temperature
–
No sea nearby – no sea temperature.
Extremes: Highest temperature 24.0 °C (4 Sep 2026) · Lowest temperature -6.1 °C (27 Sep 2020) · Avg. daily peak wind 11 km/h
Weather mix of all days
- 59Sunny
- 51Partly cloudy
- 14Cloudy
- 76Light rain
- 76Rain
Summary
- On average 13.8 °C during the day and 4.8 °C at night.
- On average 15.2 rain days (Rain day = at least 1.0 mm of precipitation) with 123 mm of precipitation in total.
- Prevailing: Rain.
- Warmest year: 2026 (avg. 17.6 °C), coolest: 2017 (avg. 10.4 °C).
- Wettest year: 2025 (207 mm), driest: 2026 (42.5 mm).
- Extremes: 24.0 °C on 4 Sep 2026 and -6.1 °C on 27 Sep 2020.
Overall values from all 10 years. How is this calculated?
Charts
Temperatures per year
Average over your travel period
Precipitation & rain days
Year by year
2026
Avg. max17.6°Avg. min6.1°- Rain days
- 6 Rain days
- Precipitation
- 42.5 mm
- Avg. sunshine per day
- n/a
- Sea temperature
- –
Max 24.0 °C · Min 1.6 °C
2025
Avg. max13.3°Avg. min4.6°- Rain days
- 18 Rain days
- Precipitation
- 207 mm
- Avg. cloud cover
- 67 % cloudy
- Sea temperature
- –
Max 20.5 °C · Min -1.2 °C
2024
Avg. max11.0°Avg. min3.5°- Rain days
- 23 Rain days
- Precipitation
- 205 mm
- Avg. cloud cover
- 72 % cloudy
- Sea temperature
- –
Max 18.7 °C · Min -3.1 °C
2023
Avg. max16.6°Avg. min7.2°- Rain days
- 12 Rain days
- Precipitation
- 120 mm
- Avg. cloud cover
- 46 % cloudy
- Sea temperature
- –
Max 22.0 °C · Min -0.9 °C
2022
Avg. max12.2°Avg. min3.5°- Rain days
- 20 Rain days
- Precipitation
- 159 mm
- Avg. cloud cover
- 66 % cloudy
- Sea temperature
- –
Max 21.5 °C · Min -3.1 °C
2021
Avg. max14.2°Avg. min5.5°- Rain days
- 13 Rain days
- Precipitation
- 110 mm
- Avg. cloud cover
- 56 % cloudy
- Sea temperature
- –
Max 17.3 °C · Min 0.2 °C
2020
Avg. max13.6°Avg. min5.1°- Rain days
- 15 Rain days
- Precipitation
- 97.0 mm
- Avg. cloud cover
- 54 % cloudy
- Sea temperature
- –
Max 20.2 °C · Min -6.1 °C
2019
Avg. max13.4°Avg. min4.4°- Rain days
- 14 Rain days
- Precipitation
- 94.2 mm
- Avg. cloud cover
- 55 % cloudy
- Sea temperature
- –
Max 19.0 °C · Min -1.0 °C
2018
Avg. max15.4°Avg. min5.7°- Rain days
- 13 Rain days
- Precipitation
- 74.3 mm
- Avg. cloud cover
- 45 % cloudy
- Sea temperature
- –
Max 19.8 °C · Min -1.4 °C
2017
Avg. max10.4°Avg. min1.9°- Rain days
- 18 Rain days
- Precipitation
- 123 mm
- Avg. cloud cover
- 72 % cloudy
- Sea temperature
- –
Max 16.6 °C · Min -2.1 °C
Frequently asked questions
- How warm is it in Interlaken in September?
- Daytime highs averaged 13.8 °C, night-time lows 4.8 °C. The highest value of the past 10 years was 24.0 °C (4 Sep 2026), the lowest -6.1 °C (27 Sep 2020).
- How often does it rain in Interlaken in September?
- On average there were 15.2 rain days (at least 1 mm) with 123 mm of precipitation in total.
Check your exact travel dates
Choose your travel period – we show the weather for exactly those days.
Other destinations in September
Data sources
- Weather data
- Data obtained from the NASA Langley Research Center (LaRC) POWER Project funded through the NASA Earth Science/Applied Science Program
Reanalysis (weather model constrained by observations) on a coarse grid of about 50 km. Values represent a large area and can differ from local conditions, especially on islands, coasts and in mountains. No sunshine duration.
Reanalysis (weather model constrained by observations)
Reanalysis values represent a grid cell (approx. 25–50 km) and may differ from local measurements on coasts, islands and in mountains. - Sea temperature
- MUR SST data were provided by JPL under support by NASA MEaSUREs program; accessed via NOAA CoastWatch ERDDAP
Daily multi-scale ultra-high resolution (≈ 1 km) analysis of satellite measurements (infrared, microwave) and in-situ data. Represents the foundation temperature below the daily warm surface layer. (Satellite and in-situ analysis) - Place search
- Natural Earth (public domain) · GeoNames (CC BY 4.0) / OpenStreetMap (ODbL)