Sonoma
California, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Sonoma, CA

Neat rows of vines in a vineyard farm in Sonoma, California, the sun rays beaming through the cloudy sunset sky, and distant hilly silhouettes
Neat rows of vines in a vineyard farm in Sonoma, California, the sun rays beaming through the cloudy sunset sky, and distant hilly silhouettes
December, the first month of the winter, in Sonoma, is still a cool month, with average temperature varying between 55°F (12.8°C) and 41.4°F (5.2°C).

Temperature

The coldest month is December, with an average high-temperature of 55°F (12.8°C) and an average low-temperature of 41.4°F (5.2°C).

Humidity

In Sonoma, the average relative humidity is 73%.

Rainfall

In December, the rain falls for 10.6 days. Throughout December, 2.72" (69mm) of precipitation is accumulated. Throughout the year, in Sonoma, there are 73.3 rainfall days, and 15.47" (393mm) of precipitation is accumulated.

Daylight

The month with the shortest days in Sonoma is December, with an average of 9.5h of daylight.

Sunshine

With an average of 5.6h of sunshine, December has the least sunshine of the year.

UV index

Months with the lowest UV index in Sonoma are January, February, November and December, with an average maximum UV index of 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from the exposure to the Sun's UV rays for average individuals.
Note: In December, the average maximum UV index of 3 translate into the following recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the coldest month in Sonoma?

December is the coldest month in Sonoma, California, with an average high-temperature of 55°F (12.8°C) and an average low-temperature of 41.4°F (5.2°C).

What is the temperature in December in Sonoma?

In Sonoma, California, in December, the average high-temperature is 55°F (12.8°C), and the average low-temperature is 41.4°F (5.2°C).

What is the average humidity in December in Sonoma?

In December, the average relative humidity in Sonoma is 73%.

How much does it rain in Sonoma in December?

In December, in Sonoma, California, the rain falls for 10.6 days. Throughout December, 2.72" (69mm) of precipitation is accumulated.

What is the month with the shortest days in Sonoma?

The month with the shortest days in Sonoma is December, with an average of 9.5h of daylight.

How many hours of daylight does Sonoma have in December?

In Sonoma, California, the average length of the day in December is 9.5h.

What is the month with the least sunshine in Sonoma?

The month with the least sunshine in Sonoma is December, with an average of 5.6h of sunshine.

How many hours of sunshine does Sonoma have in December?

In Sonoma, the average sunshine in December is 5.6h.

When is the lowest UV index in Sonoma?

January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index.

How high is the UV index in December in Sonoma?

The average daily maximum UV index in December in Sonoma is 3. A UV Index estimate of 3 to 5 represents a moderate health threat from the exposure to the Sun's UV rays.
Average temperature in December - Sonoma, CA
  • Average high temperature in December: 55°F

The warmest month (with the highest average high temperature) is August (82.9°F).
The month with the lowest average high temperature is December (55°F).

  • Average low temperature in December: 41.4°F

The month with the highest average low temperature is August (54.9°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).

Average humidity in December - Sonoma, CA
  • Average humidity in December: 73%

The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (59%).

Average rainfall in December - Sonoma, CA
  • Average rainfall in December: 2.72"

The wettest month (with the highest rainfall) is February (3.43").
Driest months (with the lowest rainfall) are July and August (0.04").

Average rainfall days in December - Sonoma, CA
  • Average rainfall days in December: 10.6 days

The month with the highest number of rainy days is March (13.4 days).
The month with the lowest number of rainy days is August (0.8 days).

Average daylight in December / Average sunshine in December - Sonoma, CA
  • Average daylight in December: 9.5h

The month with the longest days is June (Average daylight: 14.8h).
The month with shortest days is December (Average daylight: 9.5h).

  • Average sunshine in December: 5.6h

The month with most sunshine is July (Average sunshine: 12h).
The month with least sunshine is December (Average sunshine: 5.6h).

Average UV index in December - Sonoma, CA
  • Average UV index in December: 3

Months with the highest UV index are June and July (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 3).