South Korea in September: where is it warmest?
In September, Daejeon is the warmest place with 26 °C by day, Sokcho the coolest with 23 °C. 8 of 9 destinations have good holiday weather.
All destinations in September, warmest first
Long-term averages for the month: daytime high, sea, sunshine and rainy days.
South Korea in September: quick answers
South Korea in September: where is it warmest?
The warmest places in September are Daejeon (26 °C), Gwangju (26 °C) and Seoul (25 °C).
South Korea in September: where is the sea warmest?
The sea is warmest at Busan (25 °C), Ulsan (25 °C) and Jeju (25 °C).
South Korea in September: where is the weather best?
The best holiday weather in September – warm, sunny and dry – is in Seoul, Daejeon and Gwangju.
South Korea month by month
South Korea: weather & best time to visit
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