December weather forecastCalifornia, PA
December
Weather in December
December, the first month of the winter in California, is also a wintry month, with temperature in the range of an average high of 40.1°F (4.5°C) and an average low of 28.8°F (-1.8°C).Temperature
In California, entering December brings a temperature decrement, reducing from November's frosty 49.6°F (9.8°C) to a cold 40.1°F (4.5°C). California experiences an average low-temperature reading of 28.8°F (-1.8°C) throughout December.Humidity
The average relative humidity in December in California is 83%.Rainfall
In California, in December, it is raining for 14 days, with typically 3.07" (78mm) of accumulated precipitation. Throughout the year, there are 191.3 rainfall days, and 35.24" (895mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 12.6 days. Throughout December, 4.88" (124mm) of snow is accumulated. Throughout the year, there are 60.2 snowfall days, and 25.08" (637mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of December in California, sunrise is at 7:23 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:41 am and sunset at 5:04 pm EST.
Sunshine
In December, the average sunshine is 3.6h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index, 1 in December, converts into the following recommendations:
Children necessitate constant protection from sunlight, unlike the majority, who can remain under the sun for about an hour without burning. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
California, PA
- Average high temperature in December: 40.1°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in December: 28.8°F
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).
Average pressure in December
California, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
California, PA
- Average wind speed in December: 7.3mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).
Average humidity in December
California, PA
- Average humidity in December: 83%
The months with the highest relative humidity are January and February (84%).
The month with the lowest relative humidity is August (76%).
Average rainfall in December
California, PA
- Average rainfall in December: 3.07"
The wettest month (with the highest rainfall) is May (3.78").
The driest month (with the least rainfall) is November (2.13").
Average rainfall days in December
California, PA
- Average rainfall days in December: 14 days
The month with the highest number of rainy days is May (21.8 days).
The months with the least rainy days are January and February (11.7 days).
Average snowfall in December
California, PA
- Average snowfall in December: 4.88"
The month with the highest snowfall is January (6.26").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
California, PA
- Average snowfall days in December: 12.6 days
The month with the highest number of snowfall days is January (17.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
California, PA
- Average daylight in December: 9h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 3h and 36min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in December
California, PA
- Average sunshine days in December: 9.9 days
The month with the most sunshine days is November (14.3 days).
The month with the least sunshine days is January (6.8 days).
Average UV index in December
California, PA
- Average UV index in December: 1
The months with the highest UV index are May, June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
California, PA
- Average cloud cover in December: 64
The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in December
California, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, August and November (6mi).
The months with the lowest visibility are January and February (4mi).
