This report describes the typical weather at the Kadena Air Base (Okinawa, Japan) weather station over the course of an average December. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Okinawa has a warm humid temperate climate with hot summers and no dry season. The area within 25 mi of this station is covered by oceans and seas (85%), croplands (8%), and forests (7%).
The month of December is characterized by falling daily high temperatures, with daily highs decreasing from 73°F to 68°F over the course of the month, exceeding 79°F or dropping below 62°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 15 with 10:30 hours of daylight; the longest day is December 1 with 10:36 hours of daylight.
The earliest sunrise is at 7:00am on December 1; the latest sunset is at 5:47pm on December 31; the latest sunrise is at 7:17am on December 31; the earliest sunset is at 5:36pm on December 1.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover ranges from 78% (partly cloudy) to 84% (mostly cloudy). The trend is for the sky to be becoming cloudier with the median cloud cover increasing by 6% from the start to the end of the month.
On December 16, a representative day, the sky is clear or mostly clear 14% of the time, partly cloudy 12% of the time, and mostly cloudy or overcast 33% of the time.
The average probability that some form of precipitation will be observed in a given day is 67%, with little variation over the course of the month.
Throughout December, the most common forms of precipitation are moderate rain and light rain.
Moderate rain is the most severe precipitation observed during 55% of those days with precipitation. It is most likely around December 28, when it is observed during 39% of all days.
Light rain is the most severe precipitation observed during 36% of those days with precipitation. It is most likely around December 1, when it is observed during 25% of all days.
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 55% (mildly humid) to 85% (humid) over the course of a typical December, rarely dropping below 42% (comfortable) and reaching as high as 98% (very humid).
The air is driest around December 24, at which time the relative humidity drops below 61% (mildly humid) three days out of four; it is most humid around December 29, rising above 78% (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 47°F (dry) to 61°F (comfortable) and is rarely below 38°F (dry) or above 70°F (muggy).
The time of the month between December 1 and December 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of December typical wind speeds vary from 3 mph to 16 mph (light air to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 10 mph (gentle breeze) occurs around December 1, at which time the average daily maximum wind speed is 16 mph (moderate breeze).
The lowest average wind speed of 9 mph (gentle breeze) occurs around December 28, at which time the average daily maximum wind speed is 15 mph (moderate breeze).