The highest day temperature in September 2023 was 93°F. The lowest night temperature was 45°F. The average values for day and night temperatures during September were 75.3°F и 62.1°F respectivly.

The average sea surface temperature in September 2023 for Groton was 70.8°F. The maximum and minimum values were 66.2°F and 75.6°F respectively.

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

Precipitation total in September for Groton is 1.6 in. It makes september one of the most rainy months of the year.

The average wind speed in September is 7.3 mph. It makes September one of the most windless months of the year for Groton.

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 Groton in September is 7.7 hours.