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Rainy season starts on Jeju as KMA urges caution nationwide

Published: 12 Jun. 2025, 13:30 Updated: 12 Jun. 2025, 20:02

Visitors walk along a trail at Mount Songak in Daejeong-eup, Seogwipo, Jeju, on June 12 as the rainy season starts on the island. [YONHAP]

Jeju Island has officially entered the rainy season on Thursday, with the seasonal rain front pushing northward. The Korea Meteorological Administration (KMA) forecasts that rain will spread across the country over the weekend, reaching Seoul and other regions.

Rain clouds formed south of Jeju are moving northeast at a speed of 50 kilometers per hour (31 miles per hour), bringing light rainfall of about 1 millimeter per hour (0.04 inches per hour) to the island, according to the KMA.

The average start date for Jeju’s monsoon season is June 19, but this year’s rains have arrived a week earlier. This marks the third-earliest start since records began in 1973, after June 10 on both 2011 and 2020.

The rain clouds are expected to strengthen due to the inflow of tropical moisture and gradually spread across the country. “Rain will fall on Jeju starting today [June 12], reach the Chungcheong region and southern provinces tomorrow and cover the entire country the day after,” the KMA said.

Visitors walk around a garden in Andeok-myeon, Seogwipo, on Jeju Island with umbrellas on June 12, with Korea's monsoon season to start with rain on the island the same day. [YONHAP]

Heavy downpours are expected in Jeju starting Friday night, with rainfall intensities reaching 20 to 40 millimeters per hour. Through Saturday, Jeju is forecast to receive 50 to 100 millimeters of rain, with more than 200 millimeters likely on Mount Halla.

Southern coastal regions and areas near Mount Jiri may also see hourly rainfall of 10 to 30 millimeters early Saturday, with cumulative totals exceeding 100 millimeters.

“There may be gusts of wind, thunder and lightning in Jeju and along the southern coast,” a KMA official said. “Avoid areas like riverside walkways and underpasses, which could become isolated during heavy rain. Take extra caution against flooding and river overflow, especially in low-lying areas.”

Most of the rain is expected to let up by Saturday night. However, another round of rain is forecast to begin Sunday morning, starting from South Jeolla and Jeju before spreading to most of the country by the afternoon.

Rain boots and umbrellas are displayed at a supermarket in Seoul on June 12, as the rainy season starts with Jeju Island. [YONHAP]

Hot and humid conditions will continue through the weekend. Daytime highs will hover around 30 degrees Celsius (86 degrees Fahrenheit) in Seoul and other inland areas, with humidity pushing the perceived temperature even higher.

Overnight temperatures may also remain elevated, raising the possibility of this year’s first tropical nights in some regions. The KMA advises the public to stay hydrated, take breaks in shaded areas and be mindful of health risks during outdoor activities.

Meanwhile, Typhoon Wutip — this year’s first — is expected to make landfall in southern China between Friday and Saturday and weaken into a tropical depression. However, the residual moisture from the storm may flow into Korea and potentially bring another bout of heavy rain early next week.

Translated from the JoongAng Ilbo using generative AI and edited by Korea JoongAng Daily staff.
BY CHON KWON-PIL [[email protected]]