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Korea's summer monsoon to make grand comeback Wednesday with torrential downpours

Published: 15 Jul. 2025, 15:59

Tourists walk across rain-soaked ground with parasols at Imjingak in Paju, Gyeonggi on July 1. [YONHAP]

After a brief pause, Korea’s summer monsoon is set to roar back starting Wednesday, bringing days of heavy rain, flooding risks and a short reprieve from the blistering heat.

The Korea Meteorological Administration (KMA) warned Tuesday that torrential downpours of up to 50 millimeters (1.97 inches) per hour are expected overnight in the central region and North Jeolla, with widespread rainfall forecast through the weekend.

“The North Pacific high-pressure system from the east is gradually expanding, while dry air from the north is pushing southward,” said the KMA in a briefing. “Precipitation is expected across most regions nationwide from July 16 to 19 as these two air masses clash.”

As dry air from the northwest collides with hot and humid air from the southeast, a narrow band of intense rain clouds is expected to form — a typical pattern of concentrated monsoon downpours.

As a result, the central region and North Jeolla are expected to see heavy monsoon rain of 30 to 50 millimeters per hour from Wednesday evening through Thursday morning. Throughout Wednesday and Thursday, over 200 millimeters of rain is expected in southern Gyeonggi and the western coast of South Chungcheong.

Vehicles cautiously drive through spray on a road beside the Gwangjucheon in Wolsan-dong, Nam District, Gwangju, as a heavy rain advisory is issued for parts of Gwangju and South Jeolla on July 13. [NEWS1]

More than 150 millimeters is expected in the inland areas of North Chungcheong, northwestern North Jeolla and the central and southern inland areas of Gangwon. Seoul and the rest of the capital region are forecast to receive 50 to 150 millimeters of rain.

“With precipitation intensifying during nighttime hours, low-lying areas and underpasses should be prepared for possible flooding,” said Lee Chang-jae, forecast analyst at the KMA. “People should also take precautions against thunderstorms, lightning strikes and gusty winds.”

More heavy rain is expected in the southern regions and Jeju Island due to tropical moisture flowing in along the edge of the North Pacific high on Friday and Saturday. The rain is forecast to taper off nationwide by Sunday, as the high-pressure system expands over the Korean Peninsula.

People wait at a crosswalk with umbrellas at Gwanghwamun Intersection in central Seoul on June 20, as a heavy rain advisory is in effect across the city. [YONHAP]

The ongoing rainfall and a temporary influx of cooler air will keep heat wave conditions at bay through Wednesday. However, starting Thursday, muggy heat is expected to return as warm, humid southwesterly winds blow in along the edge of the high-pressure system.

From Sunday, the heat wave is forecast to resume in earnest. Daytime highs in Seoul are expected to remain around 32 to 33 degrees Celsius (89.6 to 91.4 degrees Fahrenheit) through the latter part of next week. Due to high humidity levels, afternoon showers may develop across the country amid unstable atmospheric conditions.

“After July 20, as the North Pacific high-pressure system covers the Korean Peninsula, temperatures are expected to rise again, potentially bringing another nationwide heat wave,” Lee said.

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.
BY CHON KWON-PIL [[email protected]]