On Tuesday the 4th, extreme heat is expected to continue across most of the country, with daytime highs in Seoul and Gwangju climbing to 38 C. In the Seoul metropolitan area, the highest-level heat advisory, the "Severe Heat Alert," will be issued for the first time.
According to the Korea Meteorological Administration, morning lows on the 4th are forecast at 23–27 C, with daytime highs at 30–38 C. Forecast daytime highs for major cities are 38 C in Seoul, 38 C in Gwangju, 37 C in Incheon, 37 C in Daejeon, 36 C in Daegu, and 34 C in Busan and Ulsan.
In the Seoul metropolitan area, including Seoul, and parts of South Jeolla, the Severe Heat Alert will be in effect from 11 a.m. on the 4th. The affected areas are the southeastern and southwestern districts of Seoul, Hanam, Osan, and western Yeoju in Gyeonggi, and Jangseong and northern Gokseong in South Jeolla.
The Severe Heat Alert is the highest level in the newly introduced heat advisory system this year. It is issued when areas with a maximum heat index of 35 C or higher for two or more consecutive days are expected to see a maximum heat index of at least 38 C for one or more days, or a maximum temperature of at least 39 C. This is the first time a Severe Heat Alert has been issued for the Seoul metropolitan area, including Seoul.
The Korea Meteorological Administration said extreme heat is expected to persist for the time being, especially west of the Baekdudaegan range, including the Seoul metropolitan area. As surface winds shift to easterlies, a foehn effect is occurring when air descends over the mountains and becomes hotter, pushing up temperatures in the west.
In fact, on the 3rd, temperatures exceeded 40 C at 18 Automatic Weather Stations (AWS) nationwide. Goryeong in North Gyeongsang was highest at 41.2 C, and Gwangyang-eup in South Jeolla and Sinam-dong in Dong-gu, Daegu, each recorded 41.1 C. Yangsan in South Gyeongsang, which had topped 40 C for five straight days through the previous day, eased somewhat to 39.4 C that day, but the record heat continued.
On the afternoon of the 4th, scattered showers of 5–40 mm are expected in southern Gyeonggi, North and South Chungcheong, the western inland of North Gyeongsang, and the western inland of South Gyeongsang, and 5–60 mm in Honam. Showers of around 5 mm are also forecast for the mountainous and mid-mountainous areas of Jeju, but they are unlikely to significantly lower temperatures.
The Korea Meteorological Administration urged people in areas under the Severe Heat Alert to suspend or postpone outdoor activities and outdoor work as much as possible and move indoors with air conditioning or to designated cooling centers. It also stressed the need for special caution, such as frequently checking the health of vulnerable groups to heat, including older adults, children, and people with chronic illnesses.