On Wednesday the 22nd, the entire Korean Peninsula will be affected by the monsoon front, with rain expected in most areas. In particular, the central region will see torrents of heavy rain accompanied by strong winds and lightning, while the southern region and Jeju will see a lull in the rain and face extreme heat, with daytime highs soaring to 37 degrees.
According to the Korea Meteorological Administration on the 22nd, Seoul, Incheon, the capital area including Gyeonggi, inland and mountainous Gangwon, Daejeon, Sejong, and Chungcheong Province will see 20–60 mm of rain. The expected precipitation for the five West Sea islands and the east coast of Gangwon is around 5–20 mm.
In the south, North Jeolla will see 5–40 mm, Gwangju and South Jeolla 5–30 mm, and the northern inland of North Gyeongsang 20–60 mm of rain. Daegu, North Gyeongsang, and the western inland of South Gyeongsang will see 5–40 mm, and Jeju will record around 5 mm of precipitation.
This rain will start and stop nationwide, and many places in the south will see a temporary lull during the day. In the capital area as well, there will be areas where it does not rain for a time before dawn.
Water levels in major rivers such as the Imjin, Hantan, and Bukhan, which flow through northern Gyeonggi and northern Gangwon, are expected to rise rapidly, with swifter currents. Valleys and rivers can fill up in an instant, so take thorough precautions to avoid getting stranded when passing nearby walking paths or underpasses. In addition, caution is needed to prevent damage to facilities such as flooding in low-lying areas, river overflows, landslides, and retaining wall collapses.
On the 22nd, morning lows are forecast at 22–26 degrees, with daytime highs at 29–37 degrees. With heat advisories issued for parts of Chungcheong and the south, as well as Jeju, the nationwide maximum apparent temperature will climb to around 31 degrees.
South Jeolla, South Gyeongsang and North Gyeongsang, and Jeju will soar to around 35 degrees and be very hot. At night, tropical nights with temperatures not dropping below 25 degrees will appear mainly in parts of inland Chungcheong, the south, and Jeju, causing some to have trouble sleeping.
Meanwhile, special caution is required for maritime safety. In the Yellow Sea and the East Sea, some areas will see thunder along with strong winds, and in the Yellow Sea and the South Sea, dense sea fog will roll in, reducing visibility on some islands to under 200 meters.