This report describes the typical weather at the Marine Corps Air Station Futenma (Ginowan, Japan) weather station over the course of an average year. It is based on the historical records from 1981 to 2012. Earlier records are either unavailable or unreliable.
Ginowan 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 (89%), croplands (8%), and forests (3%).
Over the course of a year, the temperature typically varies from 56Â°F to 89Â°F and is rarely below 51Â°F or above 91Â°F.
The warm season lasts from June 13 to September 30 with an average daily high temperature above 84Â°F. The hottest day of the year is July 17, with an average high of 89Â°F and low of 80Â°F.
The cold season lasts from December 12 to March 14 with an average daily high temperature below 70Â°F. The coldest day of the year is February 1, with an average low of 56Â°F and high of 65Â°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 10:30 hours of daylight; the longest day is June 20 with 13:47 hours of daylight.
The earliest sunrise is at 5:36am on June 6 and the latest sunset is at 7:26pm on June 29. The latest sunrise is at 7:19am on January 11 and the earliest sunset is at 5:36pm on November 28.
Daylight savings time (DST) is not observed in 2012.
The median cloud cover ranges from 74% (partly cloudy) to 91% (mostly cloudy). The sky is cloudiest on April 5 and clearest on September 23. The clearer part of the year begins around July 2. The cloudier part of the year begins around November 23.
On September 23, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 43% of the time, and overcast or mostly cloudy 42% of the time.
On April 5, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 73% of the time, and clear or mostly clear 12% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around May 20, occurring in 67% of days. Precipitation is least likely around October 24, occurring in 54% of days.
Over the entire year, the most common forms of precipitation are moderate rain, light rain, and thunderstorms.
Moderate rain is the most severe precipitation observed during 48% of those days with precipitation. It is most likely around February 2, when it is observed during 36% of all days.
Light rain is the most severe precipitation observed during 34% of those days with precipitation. It is most likely around February 2, when it is observed during 25% of all days.
Thunderstorms are the most severe precipitation observed during 12% of those days with precipitation. They are most likely around August 8, when it is observed during 14% of all days.
During the warm season, which lasts from June 13 to September 30, there is a 59% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of moderate rain (44% of days with precipitation have at worst moderate rain), light rain (29%), thunderstorms (21%), and heavy rain (5%).
During the cold season, which lasts from December 12 to March 14, there is a 62% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of moderate rain (54% of days with precipitation have at worst moderate rain) and light rain (38%).
Either snow is exceptionally unlikely to fall at any time during the year at this location or this station does not reliably report precipitation types.
The relative humidity typically ranges from 56% (mildly humid) to 93% (very humid) over the course of the year, rarely dropping below 43% (comfortable) and reaching as high as 100% (very humid).
The air is driest around December 10, at which time the relative humidity drops below 62% (mildly humid) three days out of four; it is most humid around June 12, exceeding 90% (very 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 year, the dew point typically varies from 46Â°F (dry) to 78Â°F (oppressive) and is rarely below 37Â°F (dry) or above 81Â°F (very oppressive).
There are two periods in the year that are most comfortable: The first is between January 1 and April 14 and the second is between November 11 and December 31. The air feels neither too dry nor too muggy during these periods.
Over the course of the year typical wind speeds vary from 2 mph to 16 mph (light air to moderate breeze), rarely exceeding 25 mph (strong breeze).
The highest average wind speed of 11 mph (gentle breeze) occurs around June 18, 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 14 mph (moderate breeze).