Seoul — Water Temperature, Sea Conditions & Trends
This page provides clear and up-to-date information about water temperature for Seoul (South Korea). It includes the current water temperature, daily data for the last month presented in a simple chart, and a 7-day forecast. The page also compares today’s value with typical averages for this period, shows usual monthly ranges during the year, and lists nearby beaches with short descriptions. Local weather for the next few days and general details about Seoul help you plan your visit and choose the best time for swimming.
Current Water Temperature
Water temperature in Seoul in the Yellow Sea today is 21°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
✅ As of today, the minimum water temperature ranges from 68°F (20°C) to 74°F (23°C). The water is warm and pleasant for swimming, and in this range, one can stay in the water for extended periods without the risk of hypothermia. This is the ideal temperature for relaxation, swimming, and water sports. Families with children, as well as outdoor enthusiasts, will enjoy swimming and time spent in the water. For most people, this is the optimal temperature for a comfortable beach experience.
It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Water Temperature Chart Over the Last 30 Days
Water temperature in Seoul today is lower than both a week ago and a month ago. Currently, the sea water temperature at this location matches the average for this day in previous years.
According to our forecast, Water temperature in Seoul will be 20.1°C in the next 7 days. See the table below for daily data for the upcoming week.
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| OCT 2 | 23.5°C | 22.8°C | |
| OCT 3 | 23.3°C | 23.0°C | |
| OCT 4 | 23.0°C | 23.0°C | |
| OCT 5 | 22.9°C | 22.8°C | |
| OCT 6 | 22.6°C | 22.8°C | |
| OCT 7 | 22.1°C | 22.3°C | |
| OCT 8 | 21.8°C | 22.3°C | |
| OCT 9 | 21.6°C | 22.3°C | |
| OCT 10 | 21.2°C | 21.8°C | 21.2°C |
| OCT 11 | 20.8°C | 21.0°C | |
| OCT 12 | 20.8°C | 20.9°C | |
| OCT 13 | 20.3°C | 20.7°C | |
| OCT 14 | 20.5°C | 20.6°C | |
| OCT 15 | 20.3°C | 20.4°C | |
| OCT 16 | 20.0°C | 20.2°C | |
| OCT 17 | 20.0°C | 20.1°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.
Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.
Water temperature data for this location is gathered from various sources, including buoys and satellite sea and ocean surface maps provided by the NOAA agency. We also incorporate data from local authorities in each specific location worldwide to ensure more accurate temperature readings.
Annual Water Temperature Overview by Month
Monthly Water Temp Ranges
Annual Water Temperature Trend
Seoul sits on the Han River and lies within a few hours’ drive of both the Yellow Sea coast to the west and the East Sea (Sea of Japan) to the east, so water temperatures near the city reflect both riverine and coastal influences. Seasonal surface temperatures around Seoul and nearby coasts vary widely: in winter seawater and river water commonly fall to about 0–5 °C, in spring they climb into roughly 5–15 °C, early summer sees temperatures rise to about 15–22 °C, and the warmest months of July and August typically bring surface waters to around 22–27 °C. Autumn cooling usually brings temperatures down to roughly 10–20 °C. Local microclimates, tidal effects and currents mean the Yellow Sea near Incheon can be a few degrees different from east coast beaches, and shallow river sections warm or cool faster than open coastal waters.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | -1°C | 4°C | 8°C |
| February | 1°C | 3°C | 5°C |
| March | 0°C | 5°C | 8°C |
| April | 4°C | 8°C | 12°C |
| May | 8°C | 13°C | 17°C |
| June | 14°C | 17°C | 22°C |
| July | 17°C | 21°C | 25°C |
| August | 20°C | 24°C | 27°C |
| September | 18°C | 23°C | 27°C |
| October | 14°C | 20°C | 25°C |
| November | 8°C | 16°C | 20°C |
| December | 2°C | 10°C | 14°C |
* Click on a month to view detailed water temperature data.
Seoul: Weather Forecast
October 11
October 12
October 13
October 14
Location, Beaches & Local Information
Swimming Conditions
Swimming directly in the Han River within Seoul is limited for safety and water quality reasons, so most residents and visitors use municipal indoor pools, seasonal outdoor public pools and water parks for cooling off. For seaside beach holidays, popular options within 1–3 hours include Incheon and Gyeonggi beaches to the west and coastal towns such as Gangneung or Sokcho to the east; these coastal spots reach their most comfortable swimming conditions in July and August when sea temperatures are usually in the mid-20s °C. Outside midsummer, waters of 15–20 °C may feel brisk and many beachgoers rely on wetsuits or stick to supervised, lifeguarded areas and organized water activities rather than open-water swimming.