Monsoon season to start early on Jeju Island from June 12

JEJU – Jeju Island is expected to witness the start of the 2025 monsoon season on June 12, with the rains expanding northwards until June 14, according to the Korea Meteorological Administration (KMA) on June 11.

On the morning of June 12, the rains are projected to fall on Jeju Island due to a stationary front – a boundary between two air masses neither of which is replacing the other, which often leads wet or unsettled weather – situated south of the region.

According to the KMA, the front formed under the influence of Typhoon Utip, the first typhoon of the summer, as it moved northwards along the western coast of the Philippines, towards southern parts of China.

The state weather agency expects the North Pacific high-pressure system to expand westwards, pushing the stationary front northwards to trigger Jeju Island’s first monsoonal rains of the season.

This year’s monsoon season is projected to have an earlier start, with Jeju Island normally seeing monsoon rains around June 19 on average.

If the weather conditions persist, 2025’s monsoonal rains will come a week earlier than usual and would mark the third-earliest monsoon season on record, trailing only 2020 and 2011’s June 10 and matching 1998’s June 12.

On June 12, the stationary front is expected to move eastwards, while hot and humid air from the east of the Philippines will flow into the Korean Peninsula along the edge of the North Pacific high-pressure system.

This will bring rainfall of up to 60mm to Jeju Island and up to 40mm to South Jeolla and South Gyeongsang provinces.

Rain clouds will also expand towards North Jeolla province and southern parts of North Gyeongsang province by late morning, bringing close to 5mm to 20mm of rainfall.

By the afternoon, North Chungcheong province as well as