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Heavy rain expected in Seoul on Wednesday and Thursday, heat to return over weekend

Published: 12 Aug. 2025, 18:26 Updated: 12 Aug. 2025, 19:08

A street in Unam-dong, Buk District in Gwangju, is flooded due to the heavy rain on Aug. 3 at night. [YONHAP]

A revived stationary front is moving north toward the central region, bringing heavy rain of up to 150 millimeters (5.9 inches) to the Seoul metropolitan area on Wednesday and Thursday. The Liberation Day holiday weekend will see a return of sweltering heat.

Lee Chang-jae, a forecaster at the Korea Meteorological Administration (KMA), said during a briefing on Tuesday that rain will be mainly concentrated from Wednesday afternoon to Thursday morning.

The stationary front currently lingering over the southern region is forecast to move north to the central area on Wednesday as the North Pacific high-pressure system expands. Moist air will flow in along the edge of the high-pressure system, while dry air from the north will clash with it, forming a strong rain band.

From Wednesday afternoon, northern Gyeonggi and northern Seoul could see torrential downpours of 30 to 50 millimeters per hour, with the rain spreading across the Seoul metropolitan area by nighttime.

Cumulative precipitation is expected to reach 50 to 120 millimeters in the greater Seoul area, and more than 150 millimeters in northern Gyeonggi. However, because the rain band will be narrow from north to south but long from east to west, rainfall amounts could vary three- to fourfold even within the same city or county.

Cars drive amid a downpour in Gwangju on Aug. 3. [NEWS1]

“The narrow, linear nature of stationary front precipitation means rainfall amounts can vary greatly depending on the exact area hit,” Lee said, adding, “Preparations are needed for heavy rain falling during vulnerable periods.”

Heavy rain is expected to weaken from Thursday afternoon, but with high moisture levels still in the atmosphere, inland areas could see sporadic showers.

From Friday, the Liberation Day holiday weekend, the North Pacific high-pressure system will dominate the Korean Peninsula, driving temperatures upward and bringing back a heat wave. Warm, humid westerly winds will raise the heat index, creating sweltering days and tropical nights.

“From Aug. 15, the North Pacific high is expected to be topped by the Tibetan high, further intensifying the heat,” Lee said, warning of the need to guard against heat-related illnesses.

This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom staff.
BY CHON KWON-PIL [[email protected]]