This report describes the typical weather at the Shimojishima Airport (Miyakojima, 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.
Miyakojima 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 (97%) and croplands (4%).
Over the course of a year, the temperature typically varies from 61Â°F to 88Â°F and is rarely below 56Â°F or above 91Â°F.
The warm season lasts from June 11 to September 28 with an average daily high temperature above 84Â°F. The hottest day of the year is July 24, with an average high of 88Â°F and low of 82Â°F.
The cold season lasts from December 12 to March 14 with an average daily high temperature below 72Â°F. The coldest day of the year is January 31, with an average low of 61Â°F and high of 68Â°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 10:36 hours of daylight; the longest day is June 20 with 13:41 hours of daylight.
The earliest sunrise is at 5:49am on June 7 and the latest sunset is at 7:33pm on July 5. The latest sunrise is at 7:26am on January 16 and the earliest sunset is at 5:49pm on November 28.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover ranges from 52% (partly cloudy) to 88% (mostly cloudy). The sky is cloudiest on January 25 and clearest on July 28. The clearer part of the year begins around June 15. The cloudier part of the year begins around October 31.
On July 28, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 17% of the time, and overcast or mostly cloudy 11% of the time.
On January 25, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 23% of the time, and clear or mostly clear 5% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around February 2, occurring in 69% of days. Precipitation is least likely around July 18, occurring in 50% 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 January 29, when it is observed during 36% of all days.
Light rain is the most severe precipitation observed during 33% of those days with precipitation. It is most likely around January 17, when it is observed during 26% of all days.
Thunderstorms are the most severe precipitation observed during 12% of those days with precipitation. They are most likely around August 13, when it is observed during 14% of all days.
During the warm season, which lasts from June 11 to September 28, there is a 54% 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 (43% of days with precipitation have at worst moderate rain), light rain (26%), thunderstorms (21%), and heavy rain (9%).
During the cold season, which lasts from December 12 to March 14, there is a 67% 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 (52% of days with precipitation have at worst moderate rain), light rain (38%), heavy rain (5%), and thunderstorms (5%).
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 60% (mildly humid) to 91% (very humid) over the course of the year, rarely dropping below 47% (comfortable) and reaching as high as 100% (very humid).
The air is driest around December 14, at which time the relative humidity drops below 66% (mildly humid) three days out of four; it is most humid around June 11, exceeding 89% (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 52Â°F (very comfortable) to 79Â°F (oppressive) and is rarely below 42Â°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 March 31 and the second is between November 21 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 7 mph to 25 mph (light breeze to strong breeze), rarely exceeding 35 mph (high wind).
The highest average wind speed of 21 mph (fresh breeze) occurs around November 20, at which time the average daily maximum wind speed is 24 mph (fresh breeze).
The lowest average wind speed of 12 mph (moderate breeze) occurs around July 17, at which time the average daily maximum wind speed is 17 mph (moderate breeze).