South Korea: where to swim in September?
South Korea, in September: the sea is at 24.1 °C on average along the coast, from 22.7 °C to 25.6 °C depending on the spot. Where the water is warmest (25.6 °C), it is warm. Ideal for long swims and for being in the water all day.
Sea temperature, month by month
| Month | Average temperature | Depending on the spot | Where it is warmest |
|---|---|---|---|
| January | 12.3 °C | 7.3 °C – 16.4 °C | cool |
| February | 10.9 °C | 5.3 °C – 15.1 °C | cool |
| March | 10.9 °C | 6.2 °C – 14.7 °C | cold |
| April | 12.8 °C | 8.7 °C – 15.7 °C | cool |
| May | 15.6 °C | 13.4 °C – 17.5 °C | cool |
| June | 19.8 °C | 18.9 °C – 20.9 °C | pleasant |
| July | 23.2 °C | 22.0 °C – 25.1 °C | warm |
| August | 26.2 °C | 25.3 °C – 27.6 °C | very warm |
| September | 24.1 °C | 22.7 °C – 25.6 °C | warm |
| October | 21.0 °C | 19.0 °C – 23.0 °C | warm |
| November | 17.7 °C | 14.8 °C – 20.6 °C | pleasant |
| December | 14.9 °C | 10.8 °C – 18.6 °C | cool |
Compared with August, the water cools down by 2.1 °C in September. The warmest month: August (26.2 °C). The coldest: February (10.9 °C).
Nearby, in September
- Taiwan 28.4 °C · very warm
- People's Republic of China 26.3 °C · very warm
- Palau 29.5 °C · very warm
- Federated States of Micronesia 29.9 °C · very warm
- India 28.7 °C · very warm
- Marshall Islands 29.7 °C · very warm
- Australia 20.3 °C · warm
- Finland 14.1 °C · cool
- Sweden 14.7 °C · cool
- Latvia 16.2 °C · cool
And right now?
For the temperature measured right now, station by station and to the hour: South Korea: water temperature
Frequently asked questions
What is the sea temperature in September?
South Korea, in September: 24.1 °C on average along the coast, from 22.7 °C in the coolest waters to 25.6 °C in the warmest (average of the years 2011 to 2025).
Can you swim in September?
Where the water is warmest (25.6 °C), it is warm. Ideal for long swims and for being in the water all day.
What is the best month for swimming?
The water is warmest in August (26.2 °C on average) and coldest in February (10.9 °C). Where the water is warmest, it goes above 20 °C in these months: June, July, August, September, October, November.
Where is the water warmest in September?
The warmest in September: Taiwan (28.4 °C), People's Republic of China (26.3 °C), Palau (29.5 °C). The coolest: Latvia (16.2 °C).
Where do these temperatures come from?
These are averages of the sea surface temperature from 2011 to 2025, computed from NOAA satellite images (OISST, one value about every 50 km), in a 100 km strip along the coasts of the main country: distant territories (overseas, remote islands) are not counted. It is an estimate, not a measurement taken at the beach: lakes and rivers are not included.