Sejong

Planning your day in Sejong? Check out the latest weather data and forecasts right here. This information will help you prepare for any weather conditions and make your stay as comfortable as possible.

Sejong has a temperate climate with four distinct seasons, giving travelers the opportunity to enjoy the full variety of weather throughout the year. Winters here are quite cold and mostly dry, with average temperatures hovering around freezing. Spring brings a gradual and pleasant warming, bringing nature to life; towards the end of the season, rainfall increases slightly, setting the stage for summer rains.

Summer in Sejong is a hot and humid period, especially in July and August, when the thermometer often rises above +30°C. The peak of precipitation occurs during the summer months, with the frequent and heavy rains characteristic of the East Asian monsoon. Autumn, by contrast, is considered one of the best times to visit: it offers comfortable cool weather, a significant decrease in rain, and plenty of clear sunny days, ideal for walking and exploring the city.

The climate in Sejong demonstrates a pronounced change of seasons with significant temperature fluctuations throughout the year. The coldest month is traditionally January, when the average temperature is around -0.9°C, and night frosts can drop the mercury to -5.1°C. Daytime temperatures in January rarely rise above +3.4°C. The hottest period is considered to be August, with an average temperature of +26.5°C. During this time, daytime highs often reach and exceed +30.1°C. July also features high temperatures, averaging +26.0°C.

The summer months in Sejong, from June to August, are characterized as hot. In June, the average temperature stays around +23.1°C (from +18.3°C at night to +27.9°C during the day), and in July and August it gets even warmer, with night temperatures around +22.7°C to +23.0°C and daytime highs reaching +29.4°C to +30.1°C. Winter, by contrast, brings cold and frost. In December, the average temperature is +0.2°C (from -3.7°C to +4.2°C), and January, as mentioned, is the coldest. February temperatures are slightly higher, averaging +1.7°C, but night minimums can still drop to -2.8°C.

Sejong experiences noticeable diurnal temperature shifts, especially in spring and autumn. For example, in March, the difference between the average maximum (+13.3°C) and average minimum (+2.4°C) temperature is nearly 11 degrees. A similar situation occurs in April (a difference of about 11°C) and May (about 10.8°C), as well as October (about 9.3°C) and November (about 9.5°C). In summer, during July and August, daily fluctuations are somewhat smaller but still perceptible—around 6.7–7.1°C. This means that even after a hot day, evenings can be significantly cooler, which is something tourists should keep in mind.

The city of Sejong experiences a clear seasonality in precipitation distribution. The highest amount occurs during the summer months, forming a distinct wet season, while winter is characterized as the driest period of the year.

The peak of the rainy season in Sejong falls in July and August. July is the wettest month, with an average of 9 mm of precipitation and about 18 rainy days. August follows with 8 mm of precipitation and approximately 16 rainy days. During these summer months, precipitation is frequent; however, given the total amount distributed over many days, it is generally not very intense. June and September are also quite wet, with 4–5 mm of precipitation and about 10 rainy days each, serving as transitional months to the drier period.

The driest months are December, January, and February. Each of these months sees only about 1 mm of precipitation. The lowest number of rainy days is observed in December (about 4 days), while January and February have about 5 days each. Given that average temperatures in January (-0.9°C) and December (0.2°C), as well as minimums (down to -5.1°C in January), often fall below freezing, winter precipitation in Sejong is most likely to fall as snow. The spring months (March, April) and late autumn (October, November) are characterized by a moderate amount of precipitation, around 2 mm per month, with 6–7 rainy days.

When planning a trip to Sejong, prepare for its distinct seasons, each requiring a different approach to your wardrobe. In winter (December–February), it is quite cold: average temperatures stay around 0°C, and can drop to -5°C at night. Although there isn't much precipitation, be sure to pack a warm winter jacket, sweaters, thermal underwear, as well as a hat, gloves, and a scarf. Waterproof and comfortable shoes will protect you from the cold and potential dampness.

Spring (March–May) and autumn (September–November) in Sejong are transitional periods with changeable weather. In spring, the temperature gradually rises from +7°C to +18°C, while in autumn it drops from +21°C to +7°C. At these times, the principle of layering is ideal: a light jacket or windbreaker, a fleece, and T-shirts. Given the increase in rainy days, especially in May (about 9 days) and September (about 10 days), a compact umbrella or a light raincoat will be your faithful companions. This is a great time for walking, so comfortable walking shoes are a must.

Summer in Sejong (June–August) is warm and humid, with average temperatures between +23°C and +26°C, while maximums can reach +30°C. July and August are the rainiest months, with up to 16–18 wet days bringing heavy rainfall. Therefore, your luggage should definitely include light, breathable clothing made from natural fabrics, shorts, and T-shirts. Don't forget a reliable umbrella or raincoat, as well as sunscreen, a hat, and sunglasses to protect against the active summer sun. Regardless of the season, your main companion should be comfortable shoes, as Sejong is perfect for long and interesting explorations on foot.