San Bruno Weather in December

San Bruno in December averages 14°C (57°F) during the day and 7°C (45°F) at night. This is the wettest month of the year.

Rainfall in San Bruno in December

With frequent rain showers this month, having an umbrella on hand will keep you dry. Typically around 13 days of rainfall are expected, averaging 113 mm (4.4 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 San Bruno in December

In December, San Bruno sees moderate temperatures, with highs of 14°C (57°F). Nights drop to around 7°C (45°F). 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. The temperatures in December are typically the coolest of the year.

Sunshine in San Bruno in December

The month experiences a moderate amount of sunlight, with 160 hours of sunshine. This provides a nice balance between sunshine and clouds.

Wind Speed in San Bruno 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

At 13°C (55°F), the water is cool but manageable for those who don't mind a bit of a shock getting in. Most people adjust after a few minutes.

December in San Bruno 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.