Weather in South Korea for September 2025
In general, the average temperature in South Korea at the beginning of September is 27.6 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 25.1 °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.
Temperatures
Rain 🌧️
South Korea in September average weather
| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  28° | 2  27° | 3 29° | 4  28° | 5 27° | 6  27° | 7 27° |
| 8 30° | 9 31° | 10 30° | 11  30° | 12 29° | 13 27° | 14 29° |
| 15 28° | 16 27° | 17 28° | 18 30° | 19 28° | 20 26° | 21  23° |
| 22 24° | 23 24° | 24 25° | 25 25° | 26 24° | 27 25° | 28 26° |
| 29 25° | 30 26° |
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Temperatures trend during September in South Korea
September weather day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Sunny | 28° /19° | 14 mm | 7 | |
| 2 Sept. | Partly cloudy | 27° /19° | 0.7 mm | 6 | |
| 3 Sept. | Partly cloudy | 29° /20° | 2.1 mm | 7 | |
| 4 Sept. | Overcast | 28° /20° | 6.4 mm | 7 | |
| 5 Sept. | Partly cloudy | 27° /19° | 46.5 mm | 7 | |
| 6 Sept. | Patchy rain possible | 27° /20° | 32.1 mm | 6 | |
| 7 Sept. | Sunny | 27° /18° | 4.3 mm | 7 | |
| 8 Sept. | Partly cloudy | 30° /19° | 0 mm | 8 | |
| 9 Sept. | Partly cloudy | 31° /19° | 0.1 mm | 8 | |
| 10 Sept. | Partly cloudy | 30° /20° | 0 mm | 7 | |
| 11 Sept. | Cloudy | 30° /21° | 0.3 mm | 7 | |
| 12 Sept. | Cloudy | 29° /20° | 1.9 mm | 6 | |
| 13 Sept. | Sunny | 27° /20° | 4.4 mm | 6 | |
| 14 Sept. | Sunny | 29° /20° | 2.2 mm | 7 | |
| 15 Sept. | Partly cloudy | 28° /20° | 1.7 mm | 6 | |
| 16 Sept. | Sunny | 27° /19° | 5.2 mm | 6 | |
| 17 Sept. | Light rain shower | 28° /21° | 5.4 mm | 6 | |
| 18 Sept. | Light rain shower | 30° /21° | 1.7 mm | 7 | |
| 19 Sept. | Patchy rain possible | 28° /20° | 3.3 mm | 7 | |
| 20 Sept. | Sunny | 26° /17° | 6.1 mm | 6 | |
| 21 Sept. | Moderate or heavy rain shower | 23° /16° | 26.6 mm | 5 | |
| 22 Sept. | Moderate or heavy rain shower | 24° /16° | 2.5 mm | 6 | |
| 23 Sept. | Overcast | 24° /16° | 0.8 mm | 6 | |
| 24 Sept. | Sunny | 25° /15° | 0 mm | 6 | |
| 25 Sept. | Cloudy | 25° /17° | 0 mm | 6 | |
| 26 Sept. | Cloudy | 24° /17° | 5.8 mm | 6 | |
| 27 Sept. | Patchy rain possible | 25° /17° | 1.2 mm | 6 | |
| 28 Sept. | Partly cloudy | 26° /17° | 1.4 mm | 6 | |
| 29 Sept. | Sunny | 25° /17° | 7.7 mm | 7 | |
| 30 Sept. | Sunny | 26° /16° | 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.
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South Korea in September - FAQ
September rainfall patterns in South Korea
UV exposure in South Korea during September
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