What December feels like in San Diego
For San Diego, December is early winter on the calendar. Days are on the cool side, the kind of weather that suits brisk sightseeing. After dark the temperature drops clearly: nights are cool. Damp air makes the cold feel rawer than the numbers alone suggest.
Rain in San Diego in December
Wet days are occasional rather than regular, about one day in 5. Rain tends to come in heavy bursts: about 9.3 mm (0.4 in) on an average rainy day. Across the year San Diego averages about 8.3 mm per rainy day, so December is typical. December is San Diego's wettest month of the year.
Daylight and sunshine in December
In mid-December, sunrise is at about 6:43 am and sunset at about 4:44 pm (local time) — 10 h 1 min of daylight. Compared with mid-November, the day has lost 29 min. Measured sunshine covers about 84% of the daylight — skies are mostly clear.
How December compares to the rest of the year
Ranked by average high, December comes out as the 2nd coolest month in San Diego. Afternoons run 3.3°C (5.9°F) cooler than in November, with 25 mm more rain. Temperatures keep falling into January. The next month's average high: 17.7°C (63.9°F).
Who December suits
- Sightseeing: a good fit — daytime temperatures are fine for walking around.
- Parks & outdoor: a good fit — good conditions for sitting outside.
- Beach: less ideal — the sea air is too cool.
Tips for visiting San Diego in December
Versatile Layers
Mornings and evenings are cooler than midday, so dress in layers.
Light Jacket
Bring a sweater or light coat for cool afternoons.
Sunglasses
Frequent sunshine — sunglasses and a light hat.
Quick questions
How warm is San Diego in December?
Afternoons average 17.6°C (63.7°F) and nights about 9°C (48.2°F) — cool by most people's standards. It is the 2nd coolest month of the year.
Does it rain a lot in San Diego in December?
Not especially. There are about 6 rainy days (56 mm), mostly moderate rain.
What should I wear in San Diego in December?
The numbers point to versatile layers, a light jacket and sunglasses. Add a layer for after dark.
Is December or January better for visiting San Diego?
January scores better on our climate ranking (#9 of 12 vs #12), rated Great against Good. January has fewer rainy days.