This report describes the typical weather at the Wasilla Airport (Wasilla, Alaska, United States) weather station over the course of an average December. It is based on the historical records from 1998 to 2012. Earlier records are either unavailable or unreliable.
Wasilla, Alaska has a continental climate with short dry cool summers. The area within 25 mi of this station is covered by forests (59%), tundra (20%), shrublands (12%), oceans and seas (6%), and lakes and rivers (3%).
The month of December is characterized by gradually falling daily high temperatures, with daily highs decreasing from 26°F to 22°F over the course of the month, exceeding 40°F or dropping below 6°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 17 with 5:21 hours of daylight; the longest day is December 1 with 5:56 hours of daylight.
The earliest sunrise is at 9:49am on December 1; the latest sunset is at 3:48pm on December 31; the latest sunrise is at 10:19am on December 27; the earliest sunset is at 3:34pm on December 15.
Daylight savings 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 45% (partly cloudy) and does not vary substantially over the course of the month.
On December 16, a representative day, the sky is clear or mostly clear 48% of the time, partly cloudy 5% of the time, and mostly cloudy or overcast 44% of the time.
There is either very little precipitation at this location in December, or the weather station does not reliably report the conditions.
Either snow is exceptionally unlikely to fall at this location in December or this station does not reliably report precipitation types.
The relative humidity typically ranges from 52% (mildly humid) to 89% (very humid) over the course of a typical December, rarely dropping below 31% (comfortable) and reaching as high as 100% (very humid).
The air is driest around December 29, at which time the relative humidity drops below 62% (mildly humid) three days out of four; it is most humid around December 17, rising above 83% (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 -1°F (dry) to 18°F (dry) and is rarely below -21°F (dry) or above 31°F (dry).
Over the course of December typical wind speeds vary from 0 mph to 11 mph (calm to gentle breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 6 mph (light breeze) occurs around December 19, at which time the average daily maximum wind speed is 11 mph (gentle breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around December 3, at which time the average daily maximum wind speed is 10 mph (gentle breeze).