California, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Belvedere, CA

Ocean temperature

In Belvedere, California, in December, the average water temperature is 54.5°F (12.5°C).
Note: At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.


The month with the shortest days is December, with an average of 9.6h of daylight.

How cold is the water in December in Belvedere?

In Belvedere, California, the average seawater temperature in December is 54.5°F (12.5°C). Swimming in 54.5°F (12.5°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the month with the shortest days in Belvedere?

With an average of 9.6h of daylight, December has the shortest days of the year in Belvedere, California.

How many hours of daylight does Belvedere have in December?

The average length of the day in December in Belvedere is 9.6h.
Average sea temperature in December - Belvedere, CA
  • Average sea temperature in December: 54.5°F

The best month for swimming (with the highest average sea temperature) is September (57.3°F).
Coldest months (with the lowest average sea temperature) are April and June (53°F).

Average daylight in December - Belvedere, CA
  • Average daylight in December: 9.6h

The month with the longest days is June (Average daylight: 14.8h).
The month with shortest days is December (Average daylight: 9.6h).