South San Francisco Weather in December

During December, South San Francisco experiences moderate daytime temperatures of 14°C (57°F) and cooler nights around 7°C (45°F). As the wettest month of the year, expect frequent rainfall.

Rainfall in South San Francisco in December

With frequent rain showers this month, having an umbrella on hand will keep you dry. Typically, about 13 days will experience rainfall, with an average of 114 mm (4.5 in) for the month. The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.

Temperature in South San Francisco in December

December in South San Francisco sees highs of 14°C (57°F) and lows of 7°C (45°F) overnight. Even when the weather is stable, mornings and evenings can still feel distinctly cool. With overnight lows of 7°C (45°F), nights are cold. The cold air does make for deep, comfortable sleep if you have enough blankets. December is characterized by some of the mildest temperatures of the year.

Sunshine in South San Francisco in December

The area experiences a moderate amount of sunshine, with approximately 160 hours of sunlight expected. This means a decent mix of sun and overcast.

Wind Speed in South San Francisco in December

Average wind speeds reach 3 m/s (6 knots) in December, creating light breezes that feel pleasant throughout the day. Some days are calmer, while others bring slightly more active breezes.

Average water temperature in December

The water temperature is 13°C (55°F), chilly, but perfectly fine for a swim if you're not too sensitive to cold water. A short wetsuit can make longer sessions more comfortable.

December in South San Francisco has its charm, but if you're looking for destinations with pleasant temperatures and sunny skies, our weather planner can help you explore other options in the world.