The highest day temperature in August 2025 was 97°F. The lowest night temperature was 82°F. The average values for day and night temperatures during August were 92.2°F и 85.5°F respectivly.

The average sea surface temperature in August 2025 for Siesta Key was 92.8°F. The maximum and minimum values were 90.8°F and 94.6°F respectively.

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

Precipitation total in August for Siesta Key is 2.2 in. It makes august one of the most rainy months of the year.

The average wind speed in August is 8.0 mph. It makes August one of the most windless months of the year for Siesta Key.

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 Siesta Key in August is 6.7 hours.