Average Weather in Yesan South Korea
In Yesan, the summers are warm, muggy, and wet; the winters are freezing, dry, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 20°F to 85°F and is rarely below 10°F or above 91°F.
Based on the tourism score, the best times of year to visit Yesan for warm-weather activities are from late May to mid July and from mid August to late September.
The hot season lasts for 3.8 months, from May 28 to September 22, with an average daily high temperature above 75°F. The hottest day of the year is August 4, with an average high of 85°F and low of 73°F.
The cold season lasts for 3.0 months, from December 2 to March 2, with an average daily high temperature below 45°F. The coldest day of the year is January 19, with an average low of 20°F and high of 35°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 Yesan, 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 Yesan begins around September 10 and lasts for 5.5 months, ending around February 25. On October 21, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 70% of the time, and overcast or mostly cloudy 30% of the time.
The cloudier part of the year begins around February 25 and lasts for 6.5 months, ending around September 10. On July 13, the cloudiest day of the year, the sky is overcast or mostly cloudy 57% of the time, and clear, mostly clear, or partly cloudy 43% 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 Yesan varies significantly throughout the year.
The wetter season lasts 2.8 months, from June 18 to September 12, with a greater than 30% chance of a given day being a wet day. The chance of a wet day peaks at 50% on July 26.
The drier season lasts 9.2 months, from September 12 to June 18. The smallest chance of a wet day is 9% on January 23.
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 50% on July 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. Yesan experiences extreme seasonal variation in monthly rainfall.
Rain falls throughout the year in Yesan. The most rain falls during the 31 days centered around July 15, with an average total accumulation of 10.3 inches.
The least rain falls around January 13, with an average total accumulation of 0.5 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall in Yesan does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Yesan varies significantly over the course of the year. In 2018, the shortest day is December 22, with 9 hours, 39 minutes of daylight; the longest day is June 21, with 14 hours, 40 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:13 AM on June 14, and the latest sunrise is 2 hours, 32 minutes later at 7:45 AM on January 6. The earliest sunset is at 5:16 PM on December 6, and the latest sunset is 2 hours, 39 minutes later at 7:55 PM on June 29.
Daylight saving time (DST) is not observed in Yesan during 2018.
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.
Yesan experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 3.2 months, from June 13 to September 18, during which time the comfort level is muggy, oppressive, or miserable at least 24% of the time. The muggiest day of the year is July 29, with muggy conditions 96% of the time.
The least muggy day of the year is December 1, 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 Yesan experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 6.7 months, from October 26 to May 17, with average wind speeds of more than 8.4 miles per hour. The windiest day of the year is February 23, with an average hourly wind speed of 9.8 miles per hour.
The calmer time of year lasts for 5.3 months, from May 17 to October 26. The calmest day of the year is June 14, with an average hourly wind speed of 7.0 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Yesan varies throughout the year.
The wind is most often from the west for 3.9 months, from March 8 to July 4, with a peak percentage of 42% on April 9. The wind is most often from the east for 1.5 months, from August 12 to September 27, with a peak percentage of 36% on September 14. The wind is most often from the north for 5.4 months, from September 27 to March 8, with a peak percentage of 55% on January 1.
Yesan 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 3.0 months, from July 6 to October 6, with an average temperature above 69°F. The day of the year with the warmest water is August 19, with an average temperature of 76°F.
The time of year with cooler water lasts for 3.8 months, from December 27 to April 20, with an average temperature below 48°F. The day of the year with the coolest water is February 22, with an average temperature of 41°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is in Yesan throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit Yesan for general outdoor tourist activities are from late May to mid July and from mid August to late September, with a peak score in the second week of June.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Yesan for hot-weather activities is from mid July to late August, with a peak score in the first week of August.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
The growing season in Yesan typically lasts for 7.2 months (222 days), from around April 1 to around November 9, rarely starting before March 17 or after April 17, and rarely ending before October 24 or after November 25.
Time Spent in Various Temperature Bands and the Growing Season
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
Based on growing degree days alone, the first spring blooms in Yesan should appear around April 16, only rarely appearing before April 7 or after April 24.
Growing Degree Days
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 3.8 months, from April 16 to August 9, with an average daily incident shortwave energy per square meter above 5.7 kWh. The brightest day of the year is June 1, with an average of 6.5 kWh.
The darker period of the year lasts for 2.9 months, from November 8 to February 4, with an average daily incident shortwave energy per square meter below 3.1 kWh. The darkest day of the year is December 20, with an average of 2.2 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Yesan are 36.678 deg latitude, 126.843 deg longitude, and 220 ft elevation.
The topography within 2 miles of Yesan contains very significant variations in elevation, with a maximum elevation change of 1,276 feet and an average elevation above sea level of 274 feet. Within 10 miles also contains very significant variations in elevation (1,877 feet). Within 50 miles contains very significant variations in elevation (2,848 feet).
The area within 2 miles of Yesan is covered by trees (37%), cropland (27%), sparse vegetation (21%), and grassland (14%), within 10 miles by trees (31%) and cropland (30%), and within 50 miles by water (31%) and trees (27%).
This report illustrates the typical weather in Yesan, 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 6 weather stations near enough to contribute to our estimation of the temperature and dew point in Yesan.
For each station, the records are corrected for the elevation difference between that station and Yesan 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 Yesan is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Yesan and a given station.
The stations contributing to this reconstruction are: Pyongtaek Ab (29%, 36 kilometers, northeast); Mangilsan Ab (22%, 45 kilometers, northwest); Cheongju International Airport (15%, 59 kilometers, east); Songmu Ab (14%, 60 kilometers, east); Taejon (12%, 65 kilometers, southeast); and Gunsan Airport (8%, 87 kilometers, south).
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.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.