The highest day temperature in December 2025 was 84°F. The lowest night temperature was 47°F. The average values for day and night temperatures during December were 68.7°F и 55.9°F respectivly.

The average sea surface temperature in December 2025 for Santa Monica was 64.6°F. The maximum and minimum values were 63.0°F and 66.0°F respectively.

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

Precipitation total in December for Santa Monica is 1.0 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 Santa Monica in December is 7.3 hours.