The highest day temperature in September 2024 was 84°F. The lowest night temperature was 42°F. The average values for day and night temperatures during September were 64.1°F и 53.2°F respectivly.

The average sea surface temperature in September 2024 for Lake Geneva was 70.5°F. The maximum and minimum values were 65.0°F and 77.2°F respectively.

Most of the days in September are sunny but you can also expect cloudy and gloomy days.

Precipitation total in September for Lake Geneva is 2.2 in. It makes september the least rainy month of the year.

The average wind speed in September is 4.6 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 Lake Geneva in September is 8.7 hours.