Weather in South Korea for September 2025
Heavy Rain Advisory - See hour by hour.
Until now, September 2025 in South Korea has been nearly identical to the historical average, with a temperature of 28.9 °C (showing only a slight deviation of 0.4 °C).
Expect cooler weather in the next days in South Korea with the forecast suggesting a temperature of 25.6 °C, lower than the historical average.
In general, the average temperature in South Korea at the beginning of September is 27.9 °C. As the month progressed, temperatures tended to moderately fall, reaching an average of 26.6 °C by the end of September.
South Korea experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 184.5 mm.
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South Korea Weather September
What’s the Weather Like in South Korea This September?
Temperatures trend during September in South Korea
September weather in South Korea day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Sunny | 27° /20° | 13.1 mm | 7 | |
| 2 Sept. |  Patchy rain possible | 28° /20° | 0.6 mm | 6 | |
| 3 Sept. | Patchy rain possible | 29° /20° | 1.7 mm | 7 | |
| 4 Sept. | Light rain shower | 29° /20° | 6 mm | 6 | |
| 5 Sept. |  Partly cloudy | 28° /20° | 37.2 mm | 7 | |
| 6 Sept. | Patchy rain possible | 27° /20° | 26.9 mm | 6 | |
| 7 Sept. | Sunny | 27° /19° | 3.5 mm | 7 | |
| 8 Sept. | Partly cloudy | 30° /19° | 0 mm | 7 | |
| 9 Sept. | Sunny | 31° /20° | 0 mm | 8 | |
| 10 Sept. | Partly cloudy | 30° /20° | 0 mm | 7 | |
| 11 Sept. |  Cloudy | 30° /21° | 0.2 mm | 7 | |
| 12 Sept. | Cloudy | 28° /20° | 7.3 mm | 6 | |
| 13 Sept. | Light rain shower | 26° /19° | 9.6 mm | 6 | |
| 14 Sept. | Sunny | 29° /20° | 1.7 mm | 6 | |
| 15 Sept. |  Overcast | 28° /20° | 1.4 mm | 6 | |
| 16 Sept. | Sunny | 27° /19° | 5.2 mm | 6 | |
| 17 Sept. |  Moderate rain | 23° /19° | 13.1 mm | 0.4 | |
| 18 Sept. | Partly cloudy | 25° /18° | 0.1 mm | 0.9 | |
| 19 Sept. | Patchy rain possible | 22° /18° | 1 mm | 1 | |
| 20 Sept. | Patchy rain possible | 26° /18° | 0.4 mm | 0.5 | |
| 21 Sept. | Patchy rain possible | 27° /18° | 0.3 mm | 5 | |
| 22 Sept. | Sunny | 25° /19° | 0 mm | 6 | |
| 23 Sept. | Partly cloudy | 24° /18° | 0 mm | 6 | |
| 24 Sept. | Partly cloudy | 24° /19° | 0 mm | 6 | |
| 25 Sept. | Partly cloudy | 27° /17° | 0 mm | 6 | |
| 26 Sept. | Partly cloudy | 28° /20° | 0 mm | 6 | |
| 27 Sept. | Sunny | 29° /19° | 0 mm | 6 | |
| 28 Sept. | Sunny | 28° /20° | 0 mm | 6 | |
| 29 Sept. | Sunny | 24° /16° | 0 mm | 5 | |
| 30 Sept. | Sunny | 26° /15° | 0 mm | 6 | |
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Guide for South Korea in September
September in South Korea marks the transition from the hot, humid summer to the cooler, more comfortable autumn. At the beginning of September, the weather can still be quite warm, with temperatures in cities like Seoul and Busan ranging from 20° to 28°.
The humidity from the summer months lingers, making the air feel warmer than it is. However, as September progresses, the weather begins to cool down, offering a more pleasant climate for outdoor activities.
By mid-September, the temperatures start to drop, especially in the northern regions and mountainous areas like Seoraksan National Park, where temperatures can range from 15° to 23°.
The skies often clear up, providing sunny days and crisp evenings, ideal for hiking and exploring the natural beauty of the country.
Towards the end of September, the weather becomes even cooler, with temperatures in places like Jeju Island ranging from 18° to 25°. This period is particularly favored by travelers as the autumn foliage begins to appear, painting the landscapes in vibrant hues of red, orange, and yellow.
Overall, September is a favorable month to visit South Korea, offering a mix of warm and cool weather, making it suitable for both city exploration and nature excursions.
South Korea in September - FAQ
September rainfall patterns in South Korea
UV exposure in South Korea during September
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Where is South Korea?Get accurate weather forecasts for South Korea, located at latitude 37.566 and longitude 126.978. Stay updated with localized weather information tailored for South Korea.