(rainfall)
Monsoon rains are expected to begin today in Jeju as the summer brings anticipation for the rainy season.
This year, the Korea Meteorological Administration predicts the rainy season may start with rain in Jeju on the 19th.
Although Jeju will experience rain on the 19th and 20th, the ‘sweltering heat’ is expected to peak inland.
An official from the Korea Meteorological Administration stated, “It is uncertain since the North Pacific high pressure is still far south of Japan, and the hot and humid air mass remains south of China. However, some forecast models indicate frequent rain in the future, suggesting the possibility of a rainy season.”
Korea’s rainy season typically lasts from the end of June to the end of July, accounting for 15% of the annual precipitation.
The season begins earliest in Jeju and progresses toward the southern and central regions, concluding at the end of July.
This June will mainly be influenced by mobile high pressure, with occasional impacts from a passing pressure trough. There is a 50% chance that the average temperature will be higher than usual (21.5’C – 22.1’C), and precipitation levels will likely be similar to the average year (96.8-180.6 mm).
In July, as the rainy season intensifies, the North Pacific high pressure will dominate, leading to many cloudy and rainy days. There is a 40% chance that the average temperature will be similar to or higher than the usual (24.5’C – 25.5″C), and a 50% chance that precipitation will exceed the average (221.9-311.5 mm).
Last year’s rainy season began on June 25th. Frequent rains every three days led to conditions resembling tropical downpours rather than a typical rainy season. Consequently, the concept of the ‘rainy season’ has become increasingly ambiguous, with localized heavy rains falling in short periods.
An official from the Korea Meteorological Administration explained, “Traditionally, the rainy season is marked by widespread, prolonged rain predictable by the movement of the rainy season front. However, some suggest that due to climate change, the term ‘rainy season’ no longer accurately describes summer precipitation on the Korean Peninsula.”
Last year, even after the rainy season ended, significant rainfall continued. The Busan Meteorological Administration reported that the cumulative amount of rainfall was 798.7 mm, making it the third-highest observed since 1973.
The year with the most precipitation during the monsoon season in Busan was 2009 when 1044.1 mm of precipitation fell while 956.7 mm fell in 2020.