Rain Showers on the 4th Day and Weekend... Late Jangma Starting in Early July

Late June Marks the Start of the Monsoon, but This Year’s Stationary Front Arrival Is Delayed
Northwest Cold Air Meets Eastern High Pressure Causing Localized Rainfall in Inland Areas
Frequent Showers Expected Before Monsoon Due to Atmospheric Instability

On the 18th, when rain fell nationwide, citizens holding umbrellas hurried on their way to work at a crosswalk near Seoul City Hall Station. Photo by Moon Honam munonam@

[Asia Economy Reporter Han Jinju] It has been raining showers for the fourth consecutive day. Due to atmospheric instability, rain is expected in various parts of the country through the weekend. Typically, the monsoon season begins in late June, but this year it is expected to start in early July.

The Korea Meteorological Administration (KMA) forecasted on the 25th that clouds will be widespread nationwide, with scattered showers from daytime in the eastern Gyeonggi region, inland Gangwon, inland Chungcheong, and mountainous areas of Jeju Island. Precipitation amounts will range from 5 to 30mm, and hail is expected in some areas such as inland Gangwon and northern Chungbuk. Locally developed rain clouds will cause significant differences in rainfall intensity and between regions.

On the 26th, rain of about 5 to 20mm will fall from dawn to night in the central region and North Gyeongsang Province, as well as in the Yeongdong area, Jeolla region, and Gyeongsangbuk-do. The KMA explained, "There is a high possibility of scattered showers until the monsoon season begins."

Although frequent rain and showers have occurred this month, the KMA clarified that this is not the monsoon. The monsoon refers to heavy rainfall caused by the stagnation of the Okhotsk Sea air mass and the North Pacific air mass over Korea, but the stationary front has not yet reached the country.

Currently, cold and dry air is located northwest of Korea, while the North Pacific high pressure is positioned to the east. Easterly winds cause air to converge mainly in inland areas, resulting in frequent showers. The KMA stated, "The rain falling until the end of this month is not due to the stationary front," and added, "The North Pacific high pressure will not expand, nor will the stationary front move northward until early next week."

Based on the average year, the monsoon season starts on June 18 in Jeju, June 23 in the southern regions, and June 25 in the central regions. This year’s monsoon is delayed by more than a week. A July monsoon is rare, having occurred only three times in the past 30 years?in 2017, 2014, and 1992.

The frequent summer rains resemble the "skol" that occurs in tropical regions. However, while skol rains are followed by hot and humid conditions, the showers in Korea are caused by cold and dry air, resulting in cooler weather after the precipitation ends. Skol typically occurs in the afternoon as the atmosphere heats up, but in Korea, showers have fallen regardless of the time of day.

The KMA explained, "The strong showers on the 22nd and 23rd showed characteristics of falling regardless of the time of day, indicating no relation to skol."

This content was produced with the assistance of AI translation services.