This report describes the historical weather record at the Kadena Air Base (Okinawa, Japan) during the last 12 months. This station has records back to January 1948.
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%)
Daylight saving time (DST) was not observed at Okinawa during the last 12 months.
2017 is not a leap year, so it has 365 days and no February 29th. The first leap year before 2017 was 2016 and the first after will be 2020.
The summer and winter solstices and the spring and fall equinoxes mark the passing of the seasons. They fall on nearly the same day each year, with differences of a day or two depending on the year. In 2017 they occurred on:
|Spring Equinox||Monday, 20 March 2017.|
|Summer Solstice||Wednesday, 21 June 2017.|
|Fall Equinox||Friday, 22 September 2017.|
|Winter Solstice||Thursday, 21 December 2017.|
The hottest day of the last 12 months was July 29, with a high temperature of 92Â°F. For reference, on that day the average high temperature is 89Â°F and the high temperature exceeds 92Â°F only one day in ten. The hottest month of the last 12 months was July with an average daily high temperature of 89Â°F.
Relative to the average, the hottest day was January 6. The high temperature that day was 77Â°F, compared to the average of 68Â°F, a difference of 9Â°F. In relative terms the warmest month was October, with an average high temperature of 85Â°F, compared to an typical value of 83Â°F.
The longest warm spell was from October 15 to November 2, constituting 19 consecutive days with warmer than average high temperatures. The month of October had the largest fraction of warmer than average days with 87% days with higher than average high temperatures.
The coldest day of the last 12 months was February 14, with a low temperature of 42Â°F. For reference, on that day the average low temperature is 56Â°F and the low temperature drops below 49Â°F only one day in ten. The coldest month of the last 12 months was February with an average daily low temperature of 54Â°F.
Relative to the average, the coldest day was March 29. The low temperature that day was 43Â°F, compared to the average of 61Â°F, a difference of 18Â°F. In relative terms the coldest month was March, with an average low temperature of 56Â°F, compared to an typical value of 60Â°F.
The longest cold spell was from July 22 to August 3, constituting 13 consecutive days with cooler than average low temperatures. The month of February had the largest fraction of cooler than average days with 68% days with lower than average low temperatures.
The clearest month of the last 12 months was July, with 87% of days being more clear than cloudy. The longest spell of clear weather was from June 8 to July 6, constituting 29 consecutive days that were clearer than they were cloudy.
The cloudiest month of the last 12 months was January, with 68% of days being more cloudy than clear. The longest spell of cloudy weather was from January 9 to January 17, constituting 9 consecutive days that were cloudier than they were clear.
This station reports both the quantity of liquid precipitation and categorical observations of precipitation (e.g., moderate rain, or heavy snow). Both are subject to erroneous reports, but the former is particularly prone to false reports, especially ones indicating an excessive quantity of precipitation. Please bear this in mind when reading the extrema reported in this section.
The day with the largest quantity of precipitation was April 10. That day saw 5.378" of liquid (or liquid equivalent) precipitation, compared to a median value of 0.126". The month with the most precipitation was June, with 11.618", compared to a median value of 7.713".
As determined by quantitative measurements, the longest dry spell was from October 24 to November 9, constituting 17 consecutive days with no measured precipitation. The month with the largest fraction of dry days was November, with 67% of days reporting no measured precipitation at all.
The month with the largest fraction of days with at least some measured precipitation was September, with 70% of days reporting some measured precipitation.
This station reports when significant weather events (including precipitation) are visually observed at or near the station. Such events do not always correspond to measured quantities of liquid equivalent precipitation, such as when the event is near by not at the station, or in the case of solid precipitation that does not melt in the collection basin.
The day in the last 12 months with the most precipitation observations was February 26. There were 19 hourly weather reports that day (out of a maximum of 24) in which some form of precipitation was observated at or near the station. The month with the most precipitation observations was February, with 108 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from August 5 to November 15, constituting 103 consecutive days with no observed precipitation. The months of September and October were completely without observed precipitation.
The month with the largest fraction of days with at least some observed precipitation was January, with 68% of days reporting some observed precipitation.
Either snow is exceptionally rare at this location or this station did not reliably report it during the last 12 months.
Humidity is an important factor in determining how weather conditions feel to a person experiencing them. Hot and humid days feel even hotter than hot and dry days because the high level of water content in humid air discourages the evaporation of sweat from a person's skin.
When reading the graph below, keep in mind that the hottest part of the day tends to be the least humid, so the daily low (brown) traces are more relevant for understanding daytime comfort than the daily high (blue) traces, which typically occur during the night. Applying that observation, the least humid month of the last 12 months was February with an average daily low humidity of 57%, and the most humid month was June with an average daily low humidity of 94%.
But it is important to keep in mind that humidity does not tell the whole picture and the dew point is often a better measure of how comfortable a person will find a given set of weather conditions. Please see the next section for continued discussion of this point.
Dew point is the temperature below which water vapor will condense into liquid water. It is therefore also related to the rate of evaporation of liquid water. Since the evaporation of sweat is an important cooling mechanism for the human body, the dew point is an important measurement for understanding how dry, comfortable, or humid a given set of weather conditions will feel.
Generally speaking, dew points below 50Â°F will feel a bit dry to some people, but comfortable to people accustomed to dry conditions; dew points from 50Â°F to 68Â°F are fairly comfortable to most people, and dew points above 68Â°F are increasingly uncomfortable, becoming oppressive around 77Â°F.
To take some examples, and basing our categorization on the daily high dew point in the last 12 months, April had no dry days, 4 comfortable days, and 26 humid days; July had no dry days, no comfortable days, and 31 humid days; October had no dry days, no comfortable days, and 31 humid days; and January had 4 dry days, 20 comfortable days, and 7 humid days.
The highest sustained wind speed was 38 mph, occurring on October 4; the highest daily mean wind speed was 22 mph (September 26); and the highest wind gust speed was 55 mph (October 4).
The windiest month was September, with an average wind speed of 11 mph. The least windy month was August, with an average wind speed of 9 mph.
Visibility is the maximum distance at which a given reference object or light can be clearly discerned. In the United States, visibilities that are greater than or equal to 10 miles are typically reported as 10 miles.
The day of the last 12 months with the lowest average visibility was June 12, with an average visibility of 7.1 mi. The month with the lowest average visibility was April, with an average visibility of 9.4 mi. With an average visibility of 10.0 mi, the month of December had the highest average visibility.
The cloud ceiling is the altitude of the lowest layer of clouds that are at categorized as broken (mostly cloudy) or overcast (cloudy). If no such cloud layer exists then the ceiling is unlimited and no value is reported.
The day of the last 12 months with the lowest average cloud ceiling was June 12, with an average cloud ceiling of 771'. The month with the lowest average cloud ceiling was October, with an average cloud ceiling of 3707'. The month of July has the highest average cloud ceiling, with an average cloud ceiling of 10123'.