Weather in Seoul in September
September in Seoul is mild with average temperatures around 20.5°C (68.9°F). Expect significant rainfall with 138mm across approximately 10 days.
Data Note: Temperature values are 2001–2020 satellite/reanalysis grid averages from NASA POWER and may differ from airport station normals by a few degrees.
Temperature
High
24.4°C
75.9°F
Low
16.5°C
61.7°F
Precipitation
138 mm
5.4 inches
~10 rainy days
Conditions
Humidity
79%
Comparison to Adjacent Months
September is 4.5°C cooler than August, 123mm drier than August.
September is 6.4°C warmer than October, 84mm wetter than October.