The highest day temperature in September 2025 was 85°F. The lowest night temperature was 65°F. The average values for day and night temperatures during September were 75.4°F и 70.3°F respectivly.

The average sea surface temperature in September 2025 for South Bethany was 75.2°F. The maximum and minimum values were 73.8°F and 77.4°F respectively.

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

Precipitation total in September for South Bethany is 1.1 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 9.7 mph. It makes September one of the most windless months of the year for South Bethany.

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 South Bethany in September is 7.3 hours.