The highest day temperature in December 2025 was 93°F. The lowest night temperature was 66°F. The average values for day and night temperatures during December were 85.1°F и 73.4°F respectivly.

The average sea surface temperature in December 2025 for Itanhaem was 81.0°F. The maximum and minimum values were 78.2°F and 85.8°F respectively.

Most of the days in December are gloomy but you can also expect sunny days.

Precipitation total in December for Itanhaem is 3.1 in. It makes december one of the most rainy months of the year.

The average wind speed in December is 5.5 mph. This value is relatively stable throughout the year.

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 Itanhaem in December is 5.3 hours.