San Diego Weather in December
Thinking of visiting San Diego in December? Expect pleasant temperatures reaching 19°C (66°F) during the day, dropping to 9°C (48°F) at night, and be prepared for the wettest month of the year.
Rainfall in San Diego in December
This month is known for heavy rainfall, so don't forget your umbrella to stay dry. Typically around 7 days of rainfall are expected, averaging 59 mm (2.3 in) for the month. Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.
Temperature in San Diego in December
In December, San Diego gets pleasant temperatures, with highs of 19°C (66°F). Nights cool to around 9°C (48°F). Even when the weather is stable, mornings and evenings can still feel distinctly cool. With lows around 9°C (48°F), nights are cold. The upside is that cool, crisp nights are often the best for a deep sleep. While this is the time of year with slightly cooler averages, it remains comfortably warm.
Sunshine in San Diego in December
Expect sunny days throughout the month, with an estimated 231 hours of sunshine. This makes it a pleasant time to visit San Diego.December in San Diego can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our San Diego's climate page.
San Diego Temperature in December
Min Temperature
9°C (48°F)
Max Temperature
19°C (66°F)
Chance of Rain
23%
Precipitation
59 mm (2.3 in)
Rainy days
7 days
Humidity
64%
Sunshine
231 hours
Percentage Sunshine
74%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in San Diego typically stay consistent throughout December, with daily highs averaging around 19°C (66°F). Nights are cool, with lows typically ranging from 9°C (48°F) to 11°C (52°F).
Average temperatures in December
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in December
Historical weather for San Diego in December
Browse day-by-day weather records for San Diego spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
San Diego historical weather extremes in December
According to our 49 years of weather records for San Diego, the following extremes were recorded between 1976 and 2025.
- The warmest day in December was on December 12, 2010, with a maximum of 28°C (82°F).
- The coldest December day was on December 22, 1990, with a maximum of 11°C (52°F).
- The coldest night in December in San Diego was on December 8, 1978, with a minimum of 3°C (37°F).
Best Places in the United States of America in December
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in December →
perfect weather
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tolerable
unpleasant
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What to Wear in San Diego in December
Pleasant temperatures in December mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Rain gear is recommended, you can expect wet weather on multiple days. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in San Diego in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our San Diego's climate page.
Temperature Rainfall Sunshine Humidity
See the full San Diego climate overview or explore weather in the United States of America.
