The highest day temperature in September 2023 was 93°F. The lowest night temperature was 82°F. The average values for day and night temperatures during September were 88.6°F и 85.9°F respectivly.

The average sea surface temperature in September 2023 for Grand Isle was 90.5°F. The maximum and minimum values were 87.0°F and 93.2°F respectively.

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

Precipitation total in September for Grand Isle is 2.4 in. It makes september one of the most rainy months of the year.

The average wind speed in September is 10.1 mph. It makes September one of the most windless months of the year for Grand Isle.

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 Grand Isle in September is 7.0 hours.