The highest day temperature in September 2025 was 81°F. The lowest night temperature was 59°F. The average values for day and night temperatures during September were 72.0°F и 66.7°F respectivly.

The average sea surface temperature in September 2025 for Montauk was 70.8°F. The maximum and minimum values were 69.6°F and 72.4°F respectively.

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

Precipitation total in September for Montauk is 1.0 in. This value is relatively stable throughout the year.

The average wind speed in September is 10.4 mph. It makes September one of the most windless months of the year for Montauk.

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 Montauk in September is 7.7 hours.