After 5 Years Since 2019, 40 Degrees in Yeoju, Gyeonggi... 8th Highest Temperature on Record

'Dual High-Pressure Systems' Cover the Korean Peninsula

The automatic weather observation equipment installed in Jeomdong-myeon, Yeoju-si, Gyeonggi Province recorded a temperature of 40 degrees Celsius at around 3:33 PM on the 4th.

A farmer is harvesting peppers under the scorching sun in a farmland in Dasan-myeon, Goryeong-gun, Gyeongbuk.
[Image source=Yonhap News]

According to the Korea Meteorological Administration, there have been a total of eight confirmed cases where temperatures in South Korea rose to the 40-degree range. On August 1, 1942, Daegu recorded a temperature of 40 degrees, and on August 1, 2018, temperatures exceeded 40 degrees in Hongseong, Bukchuncheon, Uiseong, Yangpyeong, and Chungju. On August 14 of the same year, Uiseong's temperature again surpassed 40 degrees. On August 5, 2019, a temperature of 40.2 degrees was observed in Gosam-myeon, Anseong-si, Gyeonggi Province. Since modern meteorological observations began in Korea in 1904, the highest temperature recorded was 41 degrees in Hongcheon on August 1, 2018.

Currently, the Tibetan High Pressure and the North Pacific High Pressure systems are covering the area around the Korean Peninsula. The upper atmosphere occupied by the Tibetan High Pressure experiences adiabatic warming typical of high-pressure zones, while the middle and lower layers receive hot and humid air inflows from the North Pacific High Pressure. The air heats up under direct sunlight, causing temperatures to rise. Adiabatic warming refers to the phenomenon where the temperature increases as the volume of air contracts under adiabatic conditions. The entire atmospheric column, from the lower to the upper layers, is filled with hot air.

This may not be the 'peak period' of the Tibetan High Pressure and North Pacific High Pressure. When these two high-pressure systems are at their strongest, heatwaves also reach their peak, but it is uncommon for both high-pressure systems to peak in early August. There are predictions that even more severe heatwaves may occur in the future.