Average Weather in Yamagata Japan
In Yamagata, the summers are warm, humid, wet, and mostly cloudy and the winters are freezing, snowy, and partly cloudy. Over the course of the year, the temperature typically varies from 20°F to 81°F and is rarely below 12°F or above 88°F.
The warm season lasts for 3.2 months, from June 16 to September 21, with an average daily high temperature above 72°F. The hottest day of the year is August 8, with an average high of 81°F and low of 67°F.
The cold season lasts for 3.4 months, from December 4 to March 17, with an average daily high temperature below 43°F. The coldest day of the year is January 27, with an average low of 20°F and high of 33°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
In Yamagata, 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 Yamagata begins around September 28 and lasts for 6.6 months, ending around April 17. On November 1, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 61% of the time, and overcast or mostly cloudy 39% of the time.
The cloudier part of the year begins around April 17 and lasts for 5.4 months, ending around September 28. On July 3, the cloudiest day of the year, the sky is overcast or mostly cloudy 66% of the time, and clear, mostly clear, or partly cloudy 34% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Yamagata varies throughout the year.
The wetter season lasts 6.3 months, from June 20 to December 29, with a greater than 39% chance of a given day being a wet day. The chance of a wet day peaks at 51% on July 9.
The drier season lasts 5.7 months, from December 29 to June 20. The smallest chance of a wet day is 27% on February 19.
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 in Yamagata changes throughout the year.
Rain alone is the most common for 9.5 months, from March 4 to December 19. The highest chance of a day with rain alone is 51% on July 9.
Snow alone is the most common for 2.1 months, from December 19 to February 20. The highest chance of a day with snow alone is 19% on January 18.
Mixed snow and rain is the most common for 1.7 weeks, from February 20 to March 4. The highest chance of a day with mixed snow and rain is 14% on December 26.
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 of the year. Yamagata experiences extreme seasonal variation in monthly rainfall.
Rain falls throughout the year in Yamagata. The most rain falls during the 31 days centered around July 9, with an average total accumulation of 6.1 inches.
The least rain falls around January 28, with an average total accumulation of 0.6 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Yamagata experiences significant seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 5.6 months, from November 2 to April 20, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 7, with an average total liquid-equivalent accumulation of 1.6 inches.
The snowless period of the year lasts for 6.4 months, from April 20 to November 2. The least snow falls around July 24, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Yamagata varies significantly over the course of the year. In 2017, the shortest day is December 22, with 9 hours, 30 minutes of daylight; the longest day is June 21, with 14 hours, 50 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 4:14 AM on June 14, and the latest sunrise is 2 hours, 41 minutes later at 6:55 AM on January 6. The earliest sunset is at 4:18 PM on December 7, and the latest sunset is 2 hours, 48 minutes later at 7:05 PM on June 28.
Daylight saving time (DST) is not observed in Yamagata during 2017.
Sunrise & Sunset with Twilight
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.
Yamagata experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 2.8 months, from June 25 to September 18, during which time the comfort level is muggy, oppressive, or miserable at least 19% of the time. The muggiest day of the year is August 7, with muggy conditions 74% of the time.
The least muggy day of the year is December 6, 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 Yamagata experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.4 months, from November 20 to May 1, with average wind speeds of more than 3.9 miles per hour. The windiest day of the year is February 8, with an average hourly wind speed of 5.3 miles per hour.
The calmer time of year lasts for 6.6 months, from May 1 to November 20. The calmest day of the year is July 31, with an average hourly wind speed of 2.5 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Yamagata varies throughout the year.
The wind is most often from the east for 1.0 weeks, from August 21 to August 28, with a peak percentage of 34% on August 24. The wind is most often from the west for 12 months, from August 28 to August 21, with a peak percentage of 79% on January 1.
Yamagata 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 2.7 months, from July 15 to October 5, with an average temperature above 70°F. The day of the year with the warmest water is August 21, with an average temperature of 76°F.
The time of year with cooler water lasts for 3.8 months, from January 8 to May 1, with an average temperature below 53°F. The day of the year with the coolest water is March 10, with an average temperature of 47°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 4.3 months, from April 16 to August 24, with an average daily incident shortwave energy per square meter above 5.2 kWh. The brightest day of the year is June 2, with an average of 6.1 kWh.
The darker period of the year lasts for 3.1 months, from November 9 to February 12, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest day of the year is December 25, with an average of 1.7 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Yamagata are 38.233 deg latitude, 140.367 deg longitude, and 1,050 ft elevation.
The topography within 2 miles of Yamagata contains very significant variations in elevation, with a maximum elevation change of 1,860 feet and an average elevation above sea level of 1,015 feet. Within 10 miles contains very significant variations in elevation (5,764 feet). Within 50 miles also contains extreme variations in elevation (7,031 feet).
The area within 2 miles of Yamagata is covered by trees (71%) and cropland (18%), within 10 miles by trees (65%) and cropland (28%), and within 50 miles by trees (65%) and cropland (18%).
This report illustrates the typical weather in Yamagata, 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 is only a single weather station, Matsushima Ab, in our network suitable to be used as a proxy for the historical temperature and dew point records of Yamagata.
At a distance of 77 kilometers from Yamagata, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records.
The station records are corrected for the elevation difference between the station and Yamagata according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis.
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 .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.