December weather forecastSan Rafael, CA
December
Weather in December
December, the first month of the winter in San Rafael, is still a refreshing month, with an average temperature fluctuating between 55.4°F (13°C) and 45.3°F (7.4°C).Temperature
December is the month when San Rafael sees the lowest average temperatures, with a high of 55.4°F (13°C) and a low of 45.3°F (7.4°C).Humidity
In December, the average relative humidity in San Rafael is 73%.Rainfall
In San Rafael, in December, during 7.2 rainfall days, 0.67" (17mm) of precipitation is typically accumulated. Throughout the year, there are 48 rainfall days, and 3.94" (100mm) of precipitation is accumulated.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 7:07 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 5:01 pm PST.
Sunshine
With an average of 5.5h of sunshine, December has the least sunshine of the year.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum daily UV index, 3 in December, converts into the following recommendations:
Be vigilant - Suggestions to stave off sun damage are provided. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
San Rafael, CA
- Average high temperature in December: 55.4°F
The warmest month (with the highest average high temperature) is September (72.3°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in December: 45.3°F
The month with the highest average low temperature is September (56.1°F).
The coldest month (with the lowest average low temperature) is December (45.3°F).
Average pressure in December
San Rafael, 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
San Rafael, CA
- Average wind speed in December: 6.2mph
The windiest month (with the highest average wind speed) is May (7.8mph).
The calmest months (with the lowest average wind speed) are October and November (5.5mph).
Average humidity in December
San Rafael, CA
- Average humidity in December: 73%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is October (68%).
Average rainfall in December
San Rafael, CA
- Average rainfall in December: 0.67"
The wettest month (with the highest rainfall) is February (0.87").
The driest months (with the least rainfall) are June, July, August and September (0.04").
Average rainfall days in December
San Rafael, CA
- Average rainfall days in December: 7.2 days
The month with the highest number of rainy days is March (8.8 days).
The months with the least rainy days are June and August (1.2 days).
Average daylight in December /
Average sunshine in December
San Rafael, CA
- Average daylight in December: 9h and 36min
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 36min).
- Average sunshine in December: 5h and 30min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in December
San Rafael, CA
- Average sunshine days in December: 22.1 days
The month with the most sunshine days is June (26.4 days).
The month with the least sunshine days is March (20.7 days).
Average UV index in December
San Rafael, CA
- Average UV index in December: 3
The months with the highest UV index are April, June, July, August and September (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
San Rafael, CA
- Average cloud cover in December: 38
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is September (Cloud cover 19).
Average visibility in December
San Rafael, 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).
