December weather forecastSebastopol, CA
December
Weather in December
December, the first month of the winter in Sebastopol, is still a mild month, with an average temperature fluctuating between 41.9°F (5.5°C) and 55.6°F (13.1°C).Temperature
The month of December, characterized by an average high of 55.6°F (13.1°C) and a low of 41.9°F (5.5°C), is recognized as the coldest.Humidity
In December, the average relative humidity is 75%.Rainfall
In Sebastopol, in December, during 10.5 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. Throughout the year, there are 72.8 rainfall days, and 12.01" (305mm) of precipitation is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.On the first day of the month, sunrise is at 7:10 am and sunset at 4:50 pm. On the last day of December, sunrise is at 7:28 am and sunset at 5:01 pm PST.
Sunshine
With an average of 5.7h of sunshine, December has the least sunshine of the year.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: In December, an average UV index of 3 transforms into the following instructions:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Sebastopol, CA
- Average high temperature in December: 55.6°F
The warmest month (with the highest average high temperature) is August (79.7°F).
The month with the lowest average high temperature is December (55.6°F).
- Average low temperature in December: 41.9°F
The months with the highest average low temperature are August and September (54.7°F).
The coldest month (with the lowest average low temperature) is December (41.9°F).
Average pressure in December
Sebastopol, CA
- Average pressure in December: 30.1"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
Sebastopol, CA
- Average wind speed in December: 5.2mph
The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.9mph).
Average humidity in December
Sebastopol, CA
- Average humidity in December: 75%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (63%).
Average rainfall in December
Sebastopol, CA
- Average rainfall in December: 2.24"
The wettest month (with the highest rainfall) is February (2.64").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in December
Sebastopol, CA
- Average rainfall days in December: 10.5 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (0.8 days).
Average daylight in December /
Average sunshine in December
Sebastopol, CA
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 5h and 42min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in December
Sebastopol, CA
- Average sunshine days in December: 19.5 days
The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (17.1 days).
Average UV index in December
Sebastopol, CA
- Average UV index in December: 3
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Sebastopol, CA
- Average cloud cover in December: 37
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in December
Sebastopol, 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).
