Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average sea temperature in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The arrival of December brings an average high-temperature of an enjoyable 63.3°F (17.4°C), subtly diverging from November's 68.5°F (20.3°C). During December, San Diego observes a consistent average nighttime temperature of 52.7°F (11.5°C).Humidity
In December, the average relative humidity in San Diego, California, is 62%.Rainfall
The month with the most rainfall is December, when the rain falls for 5.8 days and typically aggregates up to 1.65" (42mm) of precipitation.Ocean temperature
In San Diego, the average seawater temperature in December is 60.4°F (15.8°C).Note: Swimming in water that is 60.4°F (15.8°C) is not enjoyable for most. Breathing becomes more challenging to manage as the water temperature dips from 69.8°F (21°C) to 59°F (15°C).
Daylight
December has the shortest days of the year in San Diego, with an average of 10h and 0min of daylight.On the first day of December in San Diego, sunrise is at 6:33 am and sunset at 4:42 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 4:53 pm PST.
Sunshine
December has the least sunshine of the year in San Diego, with an average of 6.7h of sunshine.UV index
January through March, November and December, with an average maximum UV index of 4, are months with the lowest UV index in San Diego. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum daily UV index, 4 in December, converts into the following recommendations:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in December in San Diego?
What is the average humidity in December in San Diego?
What is the wettest month in San Diego?
How many days does it rain in December in San Diego?
What is the ocean temperature in December in San Diego?
What is the month with the shortest days in San Diego?
How many hours of daylight does San Diego have in December?
What time are sunrise and sunset in December in San Diego?
What is the month with the least sunshine in San Diego?
How long on average sun shines in December in San Diego?
What are the months with the lowest UV index in San Diego?
How high is the UV index in December in San Diego?
Average temperature in December
San Diego, CA
- Average high temperature in December: 63.3°F
The warmest month (with the highest average high temperature) is August (77.4°F).
The month with the lowest average high temperature is February (63.1°F).
- Average low temperature in December: 52.7°F
The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (51.8°F).
Average pressure in December
San Diego, CA
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are June and September (29.88"Hg).
Average wind speed in December
San Diego, CA
- Average wind speed in December: 5.5mph
The windiest months (with the highest average wind speed) are April and May (6.3mph).
The calmest month (with the lowest average wind speed) is October (5.2mph).
Average humidity in December
San Diego, CA
- Average humidity in December: 62%
The month with the highest relative humidity is June (73%).
The month with the lowest relative humidity is November (59%).
Average rainfall in December
San Diego, CA
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is June (0.12").
Average rainfall days in December
San Diego, CA
- Average rainfall days in December: 5.8 days
The month with the highest number of rainy days is March (7.6 days).
The month with the least rainy days is June (2.7 days).
Average sea temperature in December
San Diego, CA
- Average sea temperature in December: 60.4°F
The best month for swimming (with the highest average sea temperature) is August (67.9°F).
The coldest month (with the lowest average sea temperature) is February (58.7°F).
Average daylight in December /
Average sunshine in December
San Diego, CA
- Average daylight in December: 10h and 0min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in December: 6h and 4min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in December
San Diego, CA
- Average sunshine days in December: 23.2 days
The month with the most sunshine days is January (24.3 days).
The month with the least sunshine days is July (20.3 days).
Average UV index in December
San Diego, CA
- Average UV index in December: 4
The months with the highest UV index are July, August and September (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).
Average cloud cover in December
San Diego, CA
- Average cloud cover in December: 24
The month with the most cloud cover is December (Cloud cover 24).
The month with the least cloud cover is August (Cloud cover 9).
Average visibility in December
San Diego, CA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
San Diego, California, USA
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