Hottest (avg)
#11 / 12
San Diego in December
December weather, climate averages, and packing tips.
Avg High
Avg Low
Rain
Daylight 10h
What to expect
As winter continues, December brings, where temperatures are dropping quickly. Daytime highs average 18°C / 64°F, dropping to 9°C / 48°F at night.
You can expect a mix of sun and cloud, with about 6 days seeing some rain.
December in context
How it compares to the rest of the year in San Diego.
Wettest (avg)
#3 / 12
Daylight Hours
#12 / 12
Windiest (avg)
#11 / 12
Highest UV
#12 / 12
Most Humid
#11 / 12
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight
- 10.0 hours
- UV index (max)
- 4
- Typical sun hours
- 06:42 – 16:45
Rain & Snow
- Total
-
- Rainy days
- 6
- Cloud cover
- 45%
- Snowfall
-
Humidity & Wind
- Humidity (avg)
- 73%
- Wind (avg)
-
- Wind (max gusts)
-
Frequently asked questions
Is December a good time to visit San Diego?
Typical December days in San Diego reach highs of 17°C (63°F) with nights around 9°C (48°F). It usually feels mild by day and cool after dark. It is among the wetter months, so it is wise to have some indoor backup plans or flexible activities.
What are temperatures like in December?
In December, you can usually expect highs of 17°C (63°F) and lows near 9°C (48°F). That means mild days and cool nights, so pack layers you can add or remove.
How much does it rain in December?
Rainfall in December averages 51 mm (2.0 in) across roughly 6 days. Overall it is a moderately wet time of year, so showers are usually brief rather than all-day downpours.
How many hours of daylight are there in December?
You can expect about 10 hours of daylight in December. Sunrise is typically around 06:42 and sunset near 16:45. Days are on the shorter side, so plan activities around limited daylight.
How strong is the sun in December?
UV levels are moderate (around 4); sunscreen and sunglasses are still a good idea.
Is it windy in December?
In December, average wind speeds are around 8 km/h (5 mph), with gusts on the windiest days reaching about 37 km/h (23 mph). On the ground, it is a gentle to moderate breeze is common, but stronger winds are not frequent.