Heavy rain in southern South Korea eased during the day on July 4, 2026, leading to a return of intense heat [1].

The sudden shift from torrential rainfall to extreme heat creates a volatile weather pattern that threatens public safety and complicates disaster management in the southern regions.

Overnight heavy rain concentrated in the southern part of the country subsided, allowing clear skies and high temperatures to return [2]. This transition led to the issuance of heat-wave warnings, known as pokyeom-teukbo, across various locations in the southern Chungcheong region [3]. Meteorologists said the heat will intensify until another rain band moves into the area [2].

In Seoul, the impact of the overnight weather was minimal. Rainfall in the city was recorded at less than one mm [4]. YTN weather caster Lee Hye-min said from the Jamsu Bridge area to provide updates on the local conditions [5].

Despite the daytime lull in many areas, the weather remains unstable. A YTN anchor said that while rain would be in a lull for many during the day, heavy precipitation is expected to return [6].

Forecasts indicate that the Gyeongbuk region is particularly vulnerable to a second wave of storms. Lee said that strong rain of up to 50 mm per hour could pour down in Gyeongbuk [7]. This volume of rainfall can lead to rapid flooding and reduced visibility on roads.

Local authorities are monitoring the situation as the country swings between two weather extremes. The rapid movement of rain bands and the immediate onset of heat waves have put regional emergency services on high alert to manage both flood risks and heat-related illnesses.

“Strong rain of up to 50 mm per hour could pour down in Gyeongbuk.”

The rapid oscillation between heavy precipitation and extreme heat in South Korea suggests a highly unstable atmospheric environment. When intense heat follows heavy rain, the remaining ground moisture can increase humidity levels, potentially amplifying the perceived temperature and increasing the risk of heat-stroke for the population in southern provinces.