Average Weather in Tokyo Japan
Tokyo has a warm humid temperate climate with hot summers and no dry season. The temperature typically varies from 36°F to 87°F over the course of the year, and is rarely below 31°F or above 93°F.
The hot season lasts for 83 days, from June 27 to September 18, with an average daily high temperature above 79°F. The hottest day of the year is August 9, with an average high of 87°F and low of 77°F.
The cool season lasts for 107 days, from December 3 to March 20, with an average daily high temperature below 56°F. The coldest day of the year is January 26, with an average low of 36°F and high of 48°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
The length of the day in Tokyo varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 44 minutes of daylight; the longest day is June 21, with 14 hours, 35 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 4:24 AM on June 13, and the latest sunrise is 2 hours, 27 minutes later at 6:51 AM on January 7. The earliest sunset is at 4:27 PM on December 6, and the latest sunset is 2 hours, 34 minutes later at 7:01 PM on June 29.
Daylight saving time (DST) is not observed in Tokyo during 2017.
Sunrise & Sunset with Twilight
In Tokyo, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Tokyo begins around October 4 and lasts for 178 days, ending around March 31. On December 27, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 76% of the time, and overcast or mostly cloudy 24% of the time.
The cloudier part of the year begins around March 31 and lasts for 187 days, ending around October 4. On June 27, the cloudiest day of the year, the sky is overcast or mostly cloudy 73% of the time, and clear, mostly clear, or partly cloudy 27% of the time.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Tokyo varies significantly throughout the year.
The wetter season lasts 219 days, from March 10 to October 15, with a greater than 31% chance of a given day being a wet day. The chance of a wet day peaks at 48% on June 24.
The drier season lasts 146 days, from October 15 to March 10. The smallest chance of a wet day is 12% on December 28.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 48% on June 24.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day in the year. Tokyo experiences very significant seasonal variation in monthly rainfall.
Rain falls throughout the year in Tokyo. The most rain falls during the 31 days centered around September 24, with an average total accumulation of 7.6 inches.
The least rain falls around December 30, with and average total accumulation of 1.7 inches.
Average Monthly Rainfall
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
Tokyo experiences very significant seasonal variation in the perceived humidity.
The muggier period of the year lasts for 109 days, from June 11 to September 28, during which time the comfort level is muggy, oppressive, or miserable at least 24% of the time. The muggiest day of the year is August 8, with muggy conditions 91% of the time.
The least muggy day of the year is December 27, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Tokyo experiences mildly seasonal variation over the course of the year.
The windier part of the year lasts for 137 days, from January 2 to May 19, with average wind speeds of more than 4.3 miles per hour. The windiest day of the year is March 25, with an average hourly wind speed of 4.9 miles per hour.
The calmer time of year lasts for 228 days, from May 19 to January 2. The calmest day of the year is August 1, with an average hourly wind speed of 3.8 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Tokyo varies throughout the year.
The wind is most often from the south for 151 days, from April 15 to September 13, with a peak percentage of 52% on July 24. The wind is most often from the east for 2 days, from September 13 to September 15, with a peak percentage of 32% on September 9. The wind is most often from the north for 212 days, from September 15 to April 15, with a peak percentage of 58% on February 16.
Tokyo is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences significant seasonal variation over the course of the year.
The time of year with warmer water lasts for 77 days, from July 14 to September 29, with an average temperature above 74°F. The day of the year with the warmest water is August 19, with an average temperature of 79°F.
The time of year with cooler water lasts for 121 days, from December 25 to April 25, with an average temperature below 61°F. The day of the year with the coolest water is February 24, with an average temperature of 57°F.
Average Water Temperature
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.
The brighter period of the year lasts for 140 days, from April 12 to August 30, with an average daily incident shortwave energy per square meter above 5.3 kWh. The brightest day of the year is May 23, with an average of 5.9 kWh.
The darker period of the year lasts for 96 days, from November 1 to February 5, with an average daily incident shortwave energy per square meter below 3.3 kWh. The darkest day of the year is December 20, with an average of 2.6 kWh.
Average Daily Incident Shortwave Solar Energy
The area within 2 miles of Tokyo is covered by artificial surfaces (94%), within 10 miles by artificial surfaces (79%), and within 50 miles by trees (33%) and cropland (26%).
The topography within 2 miles of Tokyo contains only modest variations in elevation, with a maximum elevation change of 187 feet, and an average elevation above sea level of 124 feet. Within 10 miles also contains only modest variations in elevation (381 feet). Within 50 miles contains extreme variations in elevation (6,972 feet).
This report illustrates the typical weather in Tokyo, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Tokyo.
For each station, the records are are corrected for the elevation difference between that station and Tokyo according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Tokyo is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Tokyo and a given station.
The stations contributing to this reconstruction are: Tokyo (78%, 7 kilometers, east), Iruma Ab (8%, 31 kilometers, northwest), Yokota Air Base (7%, 32 kilometers, west), and Atsugi United States Naval Air Station (7%, 34 kilometers, southwest).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .