The highest day temperature in September 2026 was 91°F. The lowest night temperature was 54°F. The average values for day and night temperatures during September were 72.4°F и 63.2°F respectivly.

The average sea surface temperature in September 2026 for Westerly was 70.4°F. The maximum and minimum values were 64.4°F and 72.6°F respectively.

You can expect various weather conditions during September. Be ready for sunny, cloudy or even gloomy days.

Precipitation total in September for Westerly is 1.2 in. This value is relatively stable throughout the year.

The average wind speed in September is 8.5 mph. It makes September one of the most windless months of the year for Westerly.

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 Westerly in September is 7.0 hours.