This report describes the typical weather at the Big Bear City (Big Bear City, California, United States) weather station over the course of an average December. It is based on the historical records from 2007 to 2012. Earlier records are either unavailable or unreliable.
Big Bear City, California has a mediterranean climate with dry hot summers and mild winters. The area within 25 mi of this station is covered by shrublands (62%), forests (31%), grasslands (4%), and built-up areas (3%).
The month of December is characterized by gradually falling daily high temperatures, with daily highs ranging from 48°F to 45°F over the course of the month, exceeding 57°F or dropping below 33°F only one day in ten.
Over the course of December, the length of the day is essentially constant. The shortest day of the month is December 21 with 9:51 hours of daylight; the longest day is December 1 with 10:02 hours of daylight.
The earliest sunrise is at 6:36am on December 1; the latest sunset is at 4:48pm on December 31; the latest sunrise is at 6:54am on December 31; the earliest sunset is at 4:37pm on December 6.
Daylight saving time is observed in 2012 but it neither starts nor ends in December, so the entire month is in standard time.
The median cloud cover is 13% (mostly clear) and does not vary substantially over the course of the month.
On December 16, a representative day, the sky is clear or mostly clear 68% of the time, partly cloudy 5% of the time, and mostly cloudy or overcast 19% of the time.
The average probability that some form of precipitation will be observed in a given day is 28%, with little variation over the course of the month.
Throughout December, the most common forms of precipitation are light snow, moderate snow, and heavy snow.
Light snow is the most severe precipitation observed during 42% of those days with precipitation. It is most likely around December 4, when it is observed during 13% of all days.
Moderate snow is the most severe precipitation observed during 30% of those days with precipitation. It is most likely around December 27, when it is observed during 10% of all days.
Heavy snow is the most severe precipitation observed during 13% of those days with precipitation. It is most likely around December 27, when it is observed during 5% of all days.
The likelihood of snow falling is highest around December 27, occurring in 25% of days.
Either snow rarely accumulates at this location in December or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 27% (dry) to 86% (very humid) over the course of a typical December, rarely dropping below 12% (very dry), or exceeding 93% (very humid).
The air is driest around December 1, at which time the relative humidity drops below 33% (comfortable) three days out of four; it is most humid around December 21, rising above 84% (humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a typical December, the dew point typically varies from 6°F (dry) to 25°F (dry) and is rarely below -6°F (dry) or above 33°F (dry).
Over the course of December typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 19 mph (fresh breeze).
The highest average wind speed of 6 mph (light breeze) occurs around December 15, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around December 31, at which time the average daily maximum wind speed is 11 mph (gentle breeze).