While last June was the hottest since weather observations began in 1973, this year has brought cool mornings and evenings continuing through late June. As the monsoon arrives later than usual, the Korean Peninsula is avoiding the early summer heat.
According to the Korea Meteorological Administration (KMA) on Monday, Seoul's morning low the previous day was 19.2 degrees Celsius, 0.7 degrees lower than the seasonal average for this time of year. With low humidity as well, the weather has been pleasant without any mugginess.
It is a stark contrast to a year ago. Last June, the national average temperature was 22.9 degrees, 1.5 degrees higher than the seasonal average, marking the hottest June on record. In particular, on June 19, the earliest-ever tropical nights occurred at 12 locations including Daejeon, Daegu, and Gwangju, and the heat wave advisory that began in the south on June 27 expanded nationwide on June 29. From June 29 to 30 that month, the nationwide daily average temperature was so high that it ranked first. This year, by contrast, there has been no news of tropical nights through late June.
Citizens are also feeling the changed weather. Many say they can sleep without turning on the air conditioner at night and that the cool mornings and evenings are good for walking.
The cause of the coolness is cold air that has descended and lingered over the Korean Peninsula. Blocked by the cold air, the edge of the North Pacific high cannot move up to Korea, and the stationary front bringing monsoon rains also remains over the waters south of Jeju.
The seasonal monsoon start dates are June 19 for Jeju, June 23 for the south, and June 25 for the central region, but Jeju and the south are already later than usual.
Typhoons No. 7 and No. 8, currently moving northward, are variables that could delay the monsoon further. This is because typhoons disrupt the edge of the North Pacific high. The KMA forecast that the pressure system would be reorganized and the outline of the high's edge would take shape only after the two typhoons completely exit to the waters south of Japan. With no monsoon rain forecast through the end of June, the nationwide monsoon is expected to begin only in July.
A monsoon starting in July is unusual. Over the past 53 years, the monsoon has started in July only twice, in 1982 and 2021. In both years, the monsoon period was short and the monsoon rain that fell inland was scarce.
