South Korea Faces Sweltering Heat And Sudden Showers

On Tuesday, June 17, 2025, South Korea faces a day marked by sweltering heat, intermittent clouds, and sudden showers mainly across inland regions, as various weather agencies have forecasted. The Korea Meteorological Administration (KMA) and multiple news outlets paint a detailed picture of a day where temperatures climb to around 30 degrees Celsius, humidity rises, and sporadic rainstorms punctuate the otherwise partly cloudy skies.

Morning temperatures across the nation will range from a mild 18 degrees Celsius in some areas to a warm 23 degrees Celsius on Jeju Island. Major cities will see lows around 20 to 22 degrees Celsius, with Seoul waking up to about 21 degrees and Busan at 20 degrees. These comfortable morning temperatures will soon give way to a more intense heat as daytime highs push close to or above 30 degrees Celsius in many places. For instance, Seoul is expected to reach 29 degrees, Daegu a toasty 31 degrees, and Jeonju and Daejeon both hitting the 30-degree mark.

But the heat is not the only story. The combination of high humidity and southerly winds will make the air feel even hotter, with some regions experiencing a "feels-like" temperature exceeding 31 degrees Celsius. This surge in humidity contributes to the sweltering conditions that residents will experience, especially in inland areas.

Adding to the day’s complexity are sudden showers forecasted primarily in inland and mountainous areas. These showers are expected to begin in the late morning and continue until evening, affecting a broad swath of the country. Regions such as the inland and mountainous parts of Gangwon Province, inland Chungcheong and Jeolla Provinces, Gyeongbuk Province, and the western inland areas of Gyeongnam Province are predicted to see rainfall amounts ranging from 5 to 40 millimeters. Notably, Daegu and Gyeongbuk could receive between 5 and 40 millimeters, while Jeonbuk inland, Gwangju, Jeonnam inland, and western Gyeongnam inland areas may see 5 to 30 millimeters.

These showers won’t be mere drizzles; they are expected to be accompanied by gusty winds and lightning, making umbrellas a must-have for those venturing outdoors. The southern regions, in particular, could experience heavier downpours, with some areas receiving up to 40 millimeters of rain. The KMA cautions that these sudden showers may bring about localized gusts and thunder, emphasizing the need for vigilance.

Meanwhile, the skies over Jeju Island will remain mostly clear, offering a respite from the clouds and rain seen elsewhere. However, dense fog is anticipated in the early morning hours, especially along the coastal areas of Incheon, northern Gyeonggi, and northern Chungnam provinces. Visibility in these zones could drop below 200 meters, while other parts of the country may experience fog with visibility under one kilometer, posing potential hazards for early commuters and travelers.

Air quality across South Korea is expected to be relatively good, with fine dust levels predicted to range from 'good' to 'normal' nationwide. This improvement is credited to favorable atmospheric conditions and the cleansing effect of the rain. Residents can breathe a little easier as the air pollution threat diminishes for the day.

Looking beyond Tuesday, the weather will continue to shift. Wednesday, June 18, promises mostly clear skies with daytime highs climbing even higher, reaching between 27 and 33 degrees Celsius. However, this calm is short-lived. By Thursday, June 19, cloud cover will increase again as a high-pressure system edges out, bringing rain to central regions and Jeju Island. The following day, Friday, June 20, rain clouds are expected to expand nationwide, potentially delivering the first monsoon rains of the summer, especially to inland areas. This wet spell is forecast to persist through the weekend, with Saturday and Sunday seeing continued cloudiness and rain, particularly in Jeonnam, Gyeongnam, and Jeju.

Reflecting on the recent weather pattern, Monday morning had been overcast with light drizzle, but Tuesday’s skies, while still cloudy early on, are expected to clear gradually. Despite the sunshine, the humidity and heat will combine to create a stifling atmosphere, particularly in urban centers and inland locales.

Weathercaster Kim Min-ji, reporting for Yonhap News Agency, highlighted the day’s dynamic weather: "Today, temperatures will rise to around 30 degrees Celsius, making it quite hot. Sudden showers are expected mainly inland, accompanied by strong winds and lightning. It’s advisable to carry a small umbrella just in case." She also noted the ongoing heatwave, remarking that "the sweltering heat of around 30 degrees will continue for a while."

As the week progresses, residents should prepare for the transition from dry, hot conditions to a wetter, more unsettled pattern. The arrival of the monsoon rains could bring relief from the heat but also challenges such as flooding and travel disruptions.

In summary, June 17, 2025, in South Korea will be a day of contrasts: rising temperatures and humidity creating a hot, sticky environment, punctuated by sudden, sometimes intense showers inland, while coastal and island areas experience clearer skies and less precipitation. Dense fog in the early hours adds a layer of caution for travelers, and air quality remains generally favorable. As the week unfolds, the weather promises to become more variable, ushering in the early stages of the summer monsoon.