The highest day temperature in September 2025 was 73°F. The lowest night temperature was 30°F. The average values for day and night temperatures during September were 54.5°F и 42.5°F respectivly.

You can expect various weather conditions during September. Be ready for sunny, cloudy or even gloomy days.

Precipitation total in September for Grindelwald is 4.0 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 3.4 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Grindelwald in September is 7.2 hours.