Seoul weather in September
Temperature, rain and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Excellent
Best time to visit: April – June, September – October
What is the weather like in Seoul in September?
In September, Seoul is warm: daytime highs average 25 °C, and nights cool down to about 18 °C. Expect around 6 hours of sunshine a day. Rain falls on about 8 days, adding up to 131 mm. All in all, September is an excellent month for a holiday in Seoul.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 58 | 81 | 88 |
| Day | 28° | 25° | 19° |
| Night | 23° | 18° | 10° |
| Sun | 5 h | 6 h | 7 h |
| Rain days | 14 | 8 | 6 |
More details for September
- Daylight
- 12 h 29 min06:13 – 18:42
- UV index
- 7 · highclear sky, noon (estimate)All months
- Muggy days
- 12 daysdew point 18 °C or moreAll months
- Wind
- 15 km/haverage daily peakAll months
- Cloud cover
- 57 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC+9Asia/Seoul
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %50 %
- Few rainy daysweight 30 %69 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Sunscreen
- Sunglasses & sun hat
- Rain jacket or umbrella
Seoul in September: quick answers
Is Seoul hot in September?
Warm rather than hot: in September, daytime highs in Seoul average 25 °C and nights cool to about 18 °C.
Does it rain much in Seoul in September?
Rain falls on about 8 days, adding up to 131 mm.
Seoul month by month
The whole year in SeoulAll destinations: South KoreaWhere to go in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences