In Seoul, the summers are long, warm, muggy, wet, and partly cloudy and the winters are short, freezing, snowy, and mostly clear. Over the course of the year, the temperature typically varies from -6°C to 30°C and is rarely below -12°C or above 33°C
Based on the , the best times of year to visit Seoul for warm-weather activities are from late May to early July and from late August to early October
Climate in Seoul
Seoul weather by month. Click on each chart for more information
The hot season lasts for 4. 0 months, from 25 May to 24 September, with an average daily high temperature above 24°C. The hottest month of the year in Seoul is August, with an average high of 29°C and low of 23°C
The cold season lasts for 2. 9 months, from 1 December to 28 February, with an average daily high temperature below 7°C. The coldest month of the year in Seoul is January, with an average low of -6°C and high of 1°C
Average High and Low Temperature in Seoul
The daily average high [red line] and low [blue line] temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures
AverageJan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. High1°C4°C10°C17°C23°C26°C28°C29°C25°C19°C11°C4°CTemp. -2°C1°C6°C13°C18°C22°C25°C26°C21°C15°C7°C0°CLow-6°C-3°C3°C9°C14°C19°C22°C23°C17°C11°C4°C-3°C
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 Seoul
Jan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. 12 am12 am2 am2 am4 am4 am6 am6 am8 am8 am10 am10 am12 pm12 pm2 pm2 pm4 pm4 pm6 pm6 pm8 pm8 pm10 pm10 pm12 am12 amNowNowfreezingfreezingvery coldcoldcoldcoolcoolwarmvery coldcomfortablefreezingfreezing
frigid -9°C freezing 0°C very cold 7°C cold 13°C cool 18°C comfortable 24°C warm 29°C hot 35°C sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight
Indianapolis, Indiana, United States [10,787 kilometres away]; The Bronx, New York, United States [11,054 kilometres]; and Aktau, Kazakhstan [6,217 kilometres] are the far-away foreign places with temperatures most similar to Seoul [view comparison]
Compare Seoul to another city
In Seoul, 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 Seoul begins around 11 September and lasts for 5. 9 months, ending around 7 March
The clearest month of the year in Seoul is October, during which on average the sky is clear, mostly clear, or partly cloudy 69% of the time
The cloudier part of the year begins around 7 March and lasts for 6. 1 months, ending around 11 September
The cloudiest month of the year in Seoul is July, during which on average the sky is overcast or mostly cloudy 53% of the time
Cloud Cover Categories in Seoul
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds
FractionJan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Cloudier34%37%43%46%45%48%53%48%40%31%33%33%Clearer66%63%57%54%55%52%47%52%60%69%67%67%
A wet day is one with at least 1 millimetre of liquid or liquid-equivalent precipitation. The chance of wet days in Seoul varies significantly throughout the year
The wetter season lasts 2. 8 months, from 18 June to 11 September, with a greater than 31% chance of a given day being a wet day. The month with the most wet days in Seoul is July, with an average of 15. 9 days with at least 1 millimetre of precipitation
The drier season lasts 9. 2 months, from 11 September to 18 June. The month with the fewest wet days in Seoul is January, with an average of 3. 1 days with at least 1 millimetre of precipitation
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Seoul is July, with an average of 15. 9 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 53% on 22 July
Daily Chance of Precipitation in Seoul
The percentage of days in which various types of precipitation are observed, excluding trace quantities. rain alone, snow alone, and mixed [both rain and snow fell in the same day]
Days ofJan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Rain2. 0d2. 4d4. 6d6. 3d7. 1d9. 2d15. 9d14. 1d8. 3d5. 4d5. 1d2. 7dMixed0. 3d0. 4d0. 3d0. 0d0. 0d0. 0d0. 0d0. 0d0. 0d0. 0d0. 1d0. 3dSnow0. 8d0. 3d0. 0d0. 0d0. 0d0. 0d0. 0d0. 0d0. 0d0. 0d0. 1d0. 5dAny3. 1d3. 1d4. 9d6. 3d7. 1d9. 2d15. 9d14. 1d8. 3d5. 4d5. 2d3. 5d
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. Seoul experiences extreme seasonal variation in monthly rainfall
Rain falls throughout the year in Seoul. The month with the most rain in Seoul is July, with an average rainfall of 295 millimetres
The month with the least rain in Seoul is January, with an average rainfall of 12 millimetres
Average Monthly Rainfall in Seoul
The average rainfall [solid line] accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average snowfall
Jan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Rainfall11. 8mm22. 5mm37. 1mm62. 9mm84. 6mm132. 9mm294. 8mm246. 4mm143. 1mm52. 8mm39. 1mm17. 7mm
Snowfall
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Seoul experiences some seasonal variation in monthly snowfall
The snowy period of the year lasts for 1. 4 months, from 26 December to 9 February, with a sliding 31-day snowfall of at least 25 millimetres. The month with the most snow in Seoul is January, with an average snowfall of 29 millimetres
The snowless period of the year lasts for 11 months, from 9 February to 26 December. The least snow falls around 17 July, with an average total accumulation of 0 millimetres
Average Monthly Snowfall in Seoul
The average snowfall [solid line] accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall
Jan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Snowfall29. 2mm22. 4mm4. 7mm0. 3mm0. 0mm0. 0mm0. 0mm0. 0mm0. 0mm0. 0mm3. 2mm20. 7mm
The length of the day in Seoul varies significantly over the course of the year. In 2023, the shortest day is 22 December, with 9 hours, 34 minutes of daylight; the longest day is 21 June, with 14 hours, 46 minutes of daylight
Hours of Daylight and Twilight in Seoul
The number of hours during which the Sun is visible [black line]. From bottom [most yellow] to top [most gray], the color bands indicate. full daylight, twilight [civil, nautical, and astronomical], and full night
Hours ofJan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Daylight9. 9h10. 8h12. 0h13. 2h14. 2h14. 7h14. 5h13. 6h12. 4h11. 2h10. 2h9. 6h
The earliest sunrise is at 5. 10 am on 14 June, and the latest sunrise is 2 hours, 37 minutes later at 7. 47 am on 6 January. The earliest sunset is at 5. 13 pm on 7 December, and the latest sunset is 2 hours, 44 minutes later at 7. 57 pm on 29 June
Daylight saving time [DST] is not observed in Seoul during 2023
Sunrise & Sunset with Twilight in Seoul
The solar day over the course of the year 2023. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights [civil, nautical, and astronomical], and night are indicated by the color bands from yellow to gray
The figure below presents a compact representation of the sun's elevation [the angle of the sun above the horizon] and azimuth [its compass bearing] for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation
Solar Elevation and Azimuth in Seoul
Jan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. 12 am12 am2 am2 am4 am4 am6 am6 am8 am8 am10 am10 am12 pm12 pm2 pm2 pm4 pm4 pm6 pm6 pm8 pm8 pm10 pm10 pm12 am12 am0000101010102020202030303030404040505050606070000010101010202020203030304040505060702976NowNow
Solar elevation and azimuth over the course of the year 2023. The black lines are lines of constant solar elevation [the angle of the sun above the horizon, in degrees]. The background color fills indicate the azimuth [the compass bearing] of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions [northeast, southeast, southwest, and northwest]
The figure below presents a compact representation of key lunar data for 2023. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars [new Moons] and blue bars [full Moons] indicate key Moon phases
Moon Rise, Set & Phases in Seoul
The time in which the moon is above the horizon [light blue area], with new moons [dark gray lines] and full moons [blue lines] indicated. The shaded overlays indicate night and civil 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
Seoul experiences extreme seasonal variation in the perceived humidity
The muggier period of the year lasts for 2. 9 months, from 17 June to 14 September, during which time the comfort level is muggy, oppressive, or miserable at least 23% of the time. The month with the most muggy days in Seoul is July, with 25. 2 days that are muggy or worse
The least muggy day of the year is 22 February, when muggy conditions are essentially unheard of
Humidity Comfort Levels in Seoul
dry 13°C comfortable 16°C humid 18°C muggy 21°C oppressive 24°C miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point
Jan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Muggy days0. 0d0. 0d0. 0d0. 0d0. 3d7. 6d25. 2d24. 0d6. 2d0. 2d0. 0d0. 0d
This section discusses the wide-area hourly average wind vector [speed and direction] at 10 metres 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 Seoul experiences mild seasonal variation over the course of the year
The windier part of the year lasts for 6. 7 months, from 25 October to 17 May, with average wind speeds of more than 13. 0 kilometres per hour. The windiest month of the year in Seoul is February, with an average hourly wind speed of 14. 9 kilometres per hour
The calmer time of year lasts for 5. 3 months, from 17 May to 25 October. The calmest month of the year in Seoul is June, with an average hourly wind speed of 11. 1 kilometres per hour
Average Wind Speed in Seoul
The average of mean hourly wind speeds [dark gray line], with 25th to 75th and 10th to 90th percentile bands
Jan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Wind Speed [kph]14. 614. 914. 714. 212. 911. 112. 411. 911. 712. 513. 914. 5
The predominant average hourly wind direction in Seoul varies throughout the year
The wind is most often from the west for 5. 4 months, from 29 January to 9 July and for 1. 2 months, from 7 October to 13 November, with a peak percentage of 45% on 9 April. The wind is most often from the east for 1. 9 months, from 10 August to 7 October, with a peak percentage of 38% on 8 September. The wind is most often from the north for 2. 5 months, from 13 November to 29 January, with a peak percentage of 44% on 1 January
Wind Direction in Seoul
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1. 6 km/h. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions [northeast, southeast, southwest, and northwest]
Seoul 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 extreme seasonal variation over the course of the year
The time of year with warmer water lasts for 3. 1 months, from 6 July to 9 October, with an average temperature above 20°C. The month of the year in Seoul with the warmest water is August, with an average temperature of 24°C
The time of year with cooler water lasts for 3. 7 months, from 23 December to 14 April, with an average temperature below 8°C. The month of the year in Seoul with the coolest water is February, with an average temperature of 4°C
Average Water Temperature in Seoul
The daily average water temperature [purple line], with 25th to 75th and 10th to 90th percentile bands
WaterJan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Temperature5°C4°C5°C8°C13°C18°C22°C24°C23°C19°C14°C9°C
To characterize how pleasant the weather is in Seoul throughout the year, we compute two travel scores
The tourism score favors clear, rainless days with perceived temperatures between 18°C and 27°C. Based on this score, the best times of year to visit Seoul for general outdoor tourist activities are from late May to early July and from late August to early October, with a peak score in the second week of June
Tourism Score in Seoul
The tourism score [filled area], and its constituents. the temperature score [red line], the cloud cover score [blue line], and the precipitation score [green line]
The beach/pool score favors clear, rainless days with perceived temperatures between 24°C and 32°C. Based on this score, the best time of year to visit Seoul for hot-weather activities is from mid July to late August, with a peak score in the second week of August
Beach/Pool Score in Seoul
The beach/pool score [filled area], and its constituents. the temperature score [red line], the cloud cover score [blue line], and the precipitation score [green line]
Methodology
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 1 millimetre of precipitation or more
Our tourism temperature score is 0 for perceived temperatures below 10°C, rising linearly to 9 for 18°C, to 10 for 24°C, falling linearly to 9 for 27°C, and to 1 for 32°C or hotter
Our beach/pool temperature score is 0 for perceived temperatures below 18°C, rising linearly to 9 for 24°C, to 10 for 28°C, falling linearly to 9 for 32°C, and to 1 for 38°C 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 [≥ 0°C] in the year [the calendar year in the Northern Hemisphere, or from 1 July until 30 June in the Southern Hemisphere]
The growing season in Seoul typically lasts for 7. 8 months [237 days], from around 20 March to around 12 November, rarely starting before 4 March or after 5 April, and rarely ending before 27 October or after 29 November
Time Spent in Various Temperature Bands and the Growing Season in Seoul
frigid -9°C freezing 0°C very cold 7°C cold 13°C cool 18°C comfortable 24°C warm 29°C hot 35°C sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within 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 10°C and a cap of 30°C
Based on growing degree days alone, the first spring blooms in Seoul should appear around 12 April, only rarely appearing before 3 April or after 22 April
Growing Degree Days in Seoul
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands
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. 6 months, from 19 April to 5 August, with an average daily incident shortwave energy per square meter above 5. 7 kWh. The brightest month of the year in Seoul is June, with an average of 6. 3 kWh
The darker period of the year lasts for 2. 9 months, from 6 November to 3 February, with an average daily incident shortwave energy per square meter below 3. 1 kWh. The darkest month of the year in Seoul is December, with an average of 2. 3 kWh
Average Daily Incident Shortwave Solar Energy in Seoul
The average daily shortwave solar energy reaching the ground per square meter [orange line], with 25th to 75th and 10th to 90th percentile bands
Jan. Feb. Mar. Apr. MayJun. Jul. Aug. Sep. Oct. Nov. Dec. Solar Energy [kWh]2. 63. 54. 65. 66. 36. 35. 85. 44. 83. 92. 82. 3
For the purposes of this report, the geographical coordinates of Seoul are 37. 566 deg. latitude, 126. 978 deg. longitude, and 38 m elevation
The topography within 3 kilometres of Seoul contains very significant variations in elevation, with a maximum elevation change of 297 metres and an average elevation above sea level of 73 metres. Within 16 kilometres contains very significant variations in elevation [808 metres]. Within 80 kilometres contains large variations in elevation [1,510 metres]
The area within 3 kilometres of Seoul is covered by artificial surfaces [42%], sparse vegetation [29%], trees [15%], and bare soil [10%], within 16 kilometres by sparse vegetation [24%] and trees [24%], and within 80 kilometres by trees [35%] and water [22%]
This report illustrates the typical weather in Seoul, based on a statistical analysis of historical hourly weather reports and model reconstructions from 1 January 1980 to 31 December 2016
Temperature and Dew Point
There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Seoul
For each station, the records are corrected for the elevation difference between that station and Seoul 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 Seoul is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Seoul and a given station
The stations contributing to this reconstruction are
To get a sense of how much these sources agree with each other, you can view a comparison of Seoul and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data
Other Data
All data relating to the Sun's position [e. g. , sunrise and sunset] are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , 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 airports and weather stations are provided by AskGeo. com
Maps are © OpenStreetMap contributors
Disclaimer
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