On Tuesday the 14th, a heat wave will continue across most of the country while rain, starting in Jeju Island, is expected to expand nationwide. Temperatures will dip somewhat while it rains, but after the rain stops, high humidity is expected to bring back the sweltering heat.
According to the Korea Meteorological Administration on the 13th, the morning low on the 14th is forecast at 23–27 degrees Celsius and the daytime high at 28–36. The maximum apparent temperature in most areas nationwide will rise to around 33, with a heat wave near 35 continuing in parts of central regions, North Jeolla, and North Gyeongsang. Many places will also see tropical nights.
Rain will begin before dawn in Jeju Island and expand to the greater Seoul area and South Chungcheong in the morning. In the afternoon it will spread to the rest of the central regions and the Jeolla area, and from night most regions nationwide are expected to see rain.
From the 14th to the 15th, expected rainfall is 30–80 millimeters in Seoul, Incheon, Gyeonggi, the five West Sea islands, inland and mountainous Gangwon, Daejeon, Sejong, South Chungcheong, and North Chungcheong. North Jeolla is 20–60 millimeters; Gwangju, South Jeolla, Daegu, North Gyeongsang, Busan, Ulsan, and South Gyeongsang are 5–40 millimeters; Jeju Island is 20–60 millimeters.
In particular, parts of northern Gyeonggi and inland and mountainous northern Gangwon may see heavy rain exceeding 100 millimeters. The mountainous areas of Jeju are also expected to receive more than 80 millimeters.
In the greater Seoul area, northern South Chungcheong, and northern North Chungcheong, heavy rain of 20–30 millimeters per hour is possible on the night of the 14th. The Korea Meteorological Administration urged people to avoid entering dangerous areas such as riverside trails and underpasses, and to take special care with facility management, citing the potential for flooding in low-lying areas, river overflows, landslides, and flash flood damage.
Winds are also expected to blow strong. Gusts are likely to intensify along the west and south coasts and in the mountainous areas of Gangwon, and some regions may see high wind advisories.
While it rains, the heat wave will ease briefly, but after the rain stops, high humidity is expected to keep the apparent temperature rising sharply again, requiring attention to health. Fine dust levels are forecast to be "good" nationwide.