South Korea expects nationwide strong rain and wind on May 26, 2026, with the heaviest precipitation hitting Jeju Island and the southern coast [1].
These weather conditions pose a significant risk of flooding and infrastructure damage in vulnerable coastal and mountainous regions. The intensity of the expected rainfall could lead to rapid water accumulation and hazardous travel conditions across the peninsula.
According to the YTN weather team, a low-pressure system moving from the southwest is driving the storm [2]. This system is bringing hot, humid air that generates intense precipitation and gusty winds [2].
Weather caster Jung Soo-hyun said that heavy rain warnings have been issued for the mountains of Jeju. She said that those areas could receive up to 250mm of rainfall by tomorrow [1].
The southern coastal areas are also expected to face significant impact. Forecasts indicate that the South coast could see up to 150mm of rain [1].
Local officials are monitoring the situation closely as hourly rainfall rates may reach 50mm [2]. An unnamed YTN anchor said that damage caused by the rain is a particular concern for Jeju Island and the southern coast [3].
The combination of high humidity and the low-pressure system is expected to create unstable atmospheric conditions. This volatility increases the likelihood of sudden, intense downpours that can overwhelm local drainage systems.
“Jeju mountainous regions could see up to 250mm of rainfall.”
The forecast indicates a high-intensity weather event driven by specific atmospheric instability. When hourly rainfall hits 50mm, it often leads to flash flooding and landslides, particularly in mountainous terrain like Jeju. The concentration of rainfall in the southwest suggests the low-pressure system is carrying significant moisture, which may disrupt transport and agriculture in the southern provinces.
