South Korea expects cloudy skies and scattered rain on May 21, 2026, with cooler temperatures and lightning forecast through the morning [1].
These weather conditions coincide with the Soman seasonal transition, which often brings fluctuating temperatures and precipitation. The shift requires commuters to prepare for sudden wind gusts and potential traffic disruptions across the central region [1, 2].
YTN caster Jung Su-hyeon said rain is currently falling across the central region and parts of North Gyeongsang Province [1]. The forecast for Seoul indicates a daytime high of 20 °C [2]. Jung said that because winds will be strong, residents should carry umbrellas and light outerwear.
Heavy rain warnings are currently in effect for the mountainous areas of Gangwon Province [2]. In these regions, rainfall intensity could reach between 10 and 20 mm per hour until the morning [2].
Total precipitation estimates vary by location. The east coast and mountains of Gangwon may see up to 80 mm of rain [2]. North Gyeongsang's northeast mountains are expected to receive up to 40 mm, while other areas will likely see between five and 30 mm [2].
Authorities have advised the public to remain cautious of lightning and strong winds during their morning commutes. The weather pattern is expected to persist as the region transitions into early summer conditions [1, 2].
“Seoul daytime temperature will reach 20 °C”
The intersection of the Soman seasonal transition and localized heavy precipitation in the Gangwon highlands creates a high risk of flash flooding and transit delays. While the overall temperature drop in Seoul is moderate, the combination of wind and rain typically increases the likelihood of urban infrastructure stress and traffic congestion during the morning rush hour.
