Weatheo

Sejong Weather by Month

Average temperatures, rainfall and humidity for Sejong, Korea, South, month by month, built from OpenWeather’s historical records. Use it to see what a typical Sejong month looks like before you travel — then check the live Sejong forecast for the days ahead.

Warmest month

August

31°C average high

Coolest month

January

-6°C average low

Wettest month

July

132 mm of rain

Driest month

January

10 mm of rain

Average temperature and rainfall in Sejong by month

Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.

MonthAvg highAvg lowRecord low / highRainfallHumidityWind
January3°C-6°C-23°C / 14°C
10 mm
69%8 km/h
February6°C-4°C-18°C / 22°C
22 mm
64%9 km/h
March13°C1°C-9°C / 26°C
32 mm
61%9 km/h
April19°C7°C-3°C / 29°C
44 mm
60%9 km/h
May24°C12°C2°C / 33°C
41 mm
65%8 km/h
June28°C18°C8°C / 36°C
57 mm
72%7 km/h
July30°C22°C14°C / 37°C
132 mm
81%7 km/h
August31°C22°C13°C / 39°C
100 mm
79%7 km/h
September26°C17°C6°C / 35°C
62 mm
78%7 km/h
October19°C9°C-3°C / 29°C
53 mm
75%7 km/h
November12°C3°C-10°C / 24°C
30 mm
73%7 km/h
December4°C-4°C-18°C / 18°C
15 mm
73%8 km/h

Best time to visit Sejong

The most comfortable time to visit Sejong is generally May to June and September, balancing mild daytime temperatures against the driest stretch of the year. The city has strongly marked seasons and rain concentrates around July, totalling about 598 mm a year.

Travellers who prefer heat should aim for August, when highs average 31°C. July is the month to avoid if rain would spoil your plans — it averages 132 mm, roughly 14× the rainfall of the driest month (January).

Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the Sejong forecast for what is happening now.