The highest day temperature in December 2025 was 82°F. The lowest night temperature was 39°F. The average values for day and night temperatures during December were 69.2°F и 60.9°F respectivly.

The average sea surface temperature in December 2025 for Mustang Island was 69.6°F. The maximum and minimum values were 65.2°F and 75.2°F respectively.

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

Precipitation total in December for Mustang Island is 0.3 in. It makes december one of the least rainy months of the year.

The average wind speed in December is 11.6 mph. It makes December one of the most windless months of the year for Mustang 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 Mustang Island in December is 5.6 hours.