Heavy rain falls on Jeju, as mainland sees dry year

From midnight on Friday until 4 p.m., an estimated 247 millimeters (9.7 inches) of rain fell in the Azalea Garden, situated on the southeastern side of Jeju Island’s Mount Halla, which stands about 1,489 meters above sea level.

In the same period, it rained 157 millimeters on the island’s volcanic peak, Witse Oreum, which sits about 1,673 meters above sea level.

Witse Oreum experienced about 5,780 millimeters of rain this year as of Thursday, while the Azalea Garden saw 5,745 millimeters of rain.

On Friday, a heavy rain warning was also issued on the mountain - a far cry from the severe drought that has affected the central parts of Korea this year.

Both areas on Jeju see high amounts of precipitation annually, and rainfall in those areas over the past decade has already exceeded the yearly national average of 1,324 millimeters by about fourfold. Annual precipitation over the last decade on Witse Oreum averaged about 5,000 millimeters, with 5,200 millimeters in Azalea Garden.

“Warm air currents and humidity traveling up from Jeju’s southern waters and over from the Yangtze River in China hits the mountain,” said Han Mi-jeong, an official from the Korea Meteorological Administration. “The ascending air current that forms turns cold and leads to heavy rain on Witse Oreum and the Azalea Garden, as well as near the bottom of the mountain,” located on the central part of the island.

The northern and southern areas on the island receive varying amounts of precipitation due to weather factors. Warm air currents release rain at the southern region of Mount Halla as they travel beyond the mountain.

While average annual precipitation over the past decade in the southern city of Seogwipo recorded 1,965 millimeters, Jeju City in the island’s north saw 1,489 millimeters of rainfall.

“The rain will stop in most regions by Saturday morning except for in some areas in the eastern part of the country, including Busan; Gangneung, Gangwon; and Uljin County, North Gyeongsang,” the Korean Meteorological Administration said on Friday.

About 30 to 70 millimeters of rain was expected to fall on the east coast of Gangwon, North and South Gyeongsang, and in South Jeolla along the southern coast. The central region, including Seoul, was anticipated to see 10 to 40 millimeters of rainfall.

BY KANG KI-HEON [koo.yurim@joongang.co.kr]