The highest day temperature in September 2025 was 89°F. The lowest night temperature was 77°F. The average values for day and night temperatures during September were 86.3°F и 79.7°F respectivly.

The average sea surface temperature in September 2025 for Isla Grande was 88.2°F. The maximum and minimum values were 87.2°F and 89.0°F respectively.

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

Precipitation total in September for Isla Grande is 7.7 in.

The average wind speed in September is 4.5 mph. It makes September the most windless month of the year for Isla Grande.

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 Isla Grande in September is 5.9 hours.