Four weather of Seoul
Weather of Seoul is cold & hot. Particularly in the winter, and a dry climate. The winter temperature is quite low, and the annual temperature difference is significant. The average temperature difference between January (the coldest month) and August (the warmest month) is up to 28 °C. In mid-winter, temperatures below -5℃ are usual, and there are days practically every year when the temperature dips to -10℃. When a cold wave comes, the temperature typically drops to -15 °C.
In midsummer, temperatures above 30°C are common, with annual averages of 32–33 °C and heat waves of 34–37 °C. In severe circumstances, it can reach 38 or 39°C, as it did in 1994 and 2018. The annual temperature fluctuation is between 50 and 55°C.
To put it simply, you can think of it as being the coldest city in the world after Moscow in the winter and as hot as Singapore in the summer.
Spring
Spring in Seoul can be roughly considered to last from mid-March to May. This is the time when the weather is the best in Seoul, with an average temperature of 10 degrees in March, 15 degrees in April, and 20 degrees in May. It’s perfect weather for light clothing. However, since this is the season when fine dust levels are high, it may be a good idea to bring a mask if you have a sensitive respiratory system.
Summer
Summer in Seoul lasts from June to August. In the summer, rainfall is concentrated due to the influence of the North Pacific air mass, making it extremely humid and hot. Flooding happens on occasion during the wet season. Heavy rains were also recorded in July 2011, 2020, and August 2022. And the heat waves are intense, with these two months, July and August, exhibiting the high heat of midsummer. The daily maximum temperature must be higher than 32–33 °C, and it must be between 34 and 36°C to be regarded as a true heat wave in seoul.
July and August are typically depressingly hot and humid. Temperatures do not drop significantly. At this time, it is hot not only during the day but also at night due to the tropical nights. At the peak of the heat wave, temperatures exceed 35 degrees during the day and 28 degrees at night.
In addition to temperature, there are other issues. It’s the rainy season and typhoons. July and August, the peak of summer, are the periods when typhoons pass at the same time as Korea’s rainy season, and floods frequently occur due to torrential rain and typhoons. In particular, the Gangnam area, which has weak drainage facilities, experiences flood damage almost every year.
If you’ve read this far, you’ll know that I don’t recommend traveling to Seoul in July and August.
Autumn
Autumn in Seoul lasts from September to early November. In September, the temperature drops from 20 degrees to 15 degrees, in October, it drops to 10 degrees, and in November, it drops below 10 degrees. This is also the season with the best weather in Korea, along with spring, and you can enjoy beautiful falling leaves. It is the only season among the four seasons in Seoul that has no drawbacks.
Winter
Winter in Seoul lasts from mid-November to February. It is a time when Siberia brings with it a cold. Winter of Seoul could not be compared to the neighboring city of Tokyo. Moscow is the only major city in the world that is definitely colder than Seoul. The average winter temperature is -5 degrees Celsius, but it is often very windy due to the northern Siberian wind, so the actual temperature is generally closer to -10 degrees Celsius. Even in mid-January, the coldest time, temperatures can sometimes reach -20 degrees Celsius. Also, it is snowing, so you have to be careful on the icy roads.
Conclusion
Weather of Seoul can be harsh, and travelers are advised to be prepared. In particular, it is not recommended to travel in July and August. The most recommended travel times are spring and fall when the weather is nice.
If you go on a trip again, please read this article about Naver Map, which is a must-have for traveling to Korea.