The highest day temperature in August 2025 was 96°F. The lowest night temperature was 83°F. The average values for day and night temperatures during August were 92.4°F и 87.2°F respectivly.

The average sea surface temperature in August 2025 for Sanibel Island was 93.2°F. The maximum and minimum values were 91.4°F and 94.4°F respectively.

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

Precipitation total in August for Sanibel Island is 2.1 in. It makes august one of the most rainy months of the year.

The average wind speed in August is 7.9 mph. It makes August one of the most windless months of the year for Sanibel Island.

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 Sanibel Island in August is 6.8 hours.