The highest day temperature in September 2026 was 72°F. The lowest night temperature was 46°F. The average values for day and night temperatures during September were 66.9°F и 57.7°F respectivly.

The average sea surface temperature in September 2026 for Harbor Springs was 70.0°F. The maximum and minimum values were 63.6°F and 74.2°F respectively.

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

Precipitation total in September for Harbor Springs is 0.7 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 7.8 mph. It makes September one of the most windless months of the year for Harbor Springs.

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 Harbor Springs in September is 7.2 hours.