December weather forecastAlameda, CA
December
Weather in December
The first month of the winter, December, is still a mild month in Alameda, California, with an average temperature varying between 45.1°F (7.3°C) and 55.9°F (13.3°C).Temperature
December, known for its average high temperature of 55.9°F (13.3°C) and an average low temperature of 45.1°F (7.3°C), is the coldest month.Humidity
The average relative humidity in December is 71%.Rainfall
In Alameda, in December, it is raining for 10.2 days, with typically 1.02" (26mm) of accumulated precipitation. In Alameda, during the entire year, the rain falls for 67.2 days and collects up to 6.1" (155mm) of precipitation.Ocean temperature
In Alameda, California, the average seawater temperature in December is 54.5°F (12.5°C).Note: Caution: 54.5°F (12.5°C) temperatures below 50°F (10°C) during swimming can result in intense cold shock and quickened breathing.
Daylight
With an average of 9h and 36min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:06 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 5:00 pm PST.
Sunshine
With an average of 5.9h of sunshine, December has the least sunshine of the year.UV index
January, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: In December, a regular UV index of 3 translates into these guidelines:
Take precautions. Light skin individuals may get burned in less than 30 minutes. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Alameda, CA
- Average high temperature in December: 55.9°F
The warmest month (with the highest average high temperature) is September (75.9°F).
The month with the lowest average high temperature is December (55.9°F).
- Average low temperature in December: 45.1°F
The month with the highest average low temperature is September (56.5°F).
The coldest month (with the lowest average low temperature) is January (45°F).
Average pressure in December
Alameda, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in December
Alameda, CA
- Average wind speed in December: 5.8mph
The windiest month (with the highest average wind speed) is May (7.2mph).
The calmest months (with the lowest average wind speed) are October and November (5.2mph).
Average humidity in December
Alameda, CA
- Average humidity in December: 71%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is October (65%).
Average rainfall in December
Alameda, CA
- Average rainfall in December: 1.02"
The wettest month (with the highest rainfall) is February (1.18").
The driest month (with the least rainfall) is July (0.04").
Average rainfall days in December
Alameda, CA
- Average rainfall days in December: 10.2 days
The month with the highest number of rainy days is March (11.4 days).
The month with the least rainy days is August (1.3 days).
Average sea temperature in December
Alameda, CA
- Average sea temperature in December: 54.5°F
The best month for swimming (with the highest average sea temperature) is September (57.3°F).
The coldest months (with the lowest average sea temperature) are April and June (53°F).
Average daylight in December /
Average sunshine in December
Alameda, CA
- Average daylight in December: 9h and 36min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 5h and 54min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in December
Alameda, CA
- Average sunshine days in December: 19.4 days
The month with the most sunshine days is July (25.4 days).
The month with the least sunshine days is March (17.3 days).
Average UV index in December
Alameda, CA
- Average UV index in December: 3
The months with the highest UV index are April, May, June, July, August and September (UV index 5).
The months with the lowest UV index are January, November and December (UV index 3).
Average cloud cover in December
Alameda, CA
- Average cloud cover in December: 34
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in December
Alameda, 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).
