The traditional calendar says the sweltering heat should be retreating. But it's not.

The seasonal term Cheoseo, which traditionally marks the retreat of summer heat, is fast approaching on Saturday — but signs of relief from the sweltering weather are nowhere to be seen.

Three days before Cheoseo, when the weather is supposed to become cooler, residents are drying peppers under the hot sun in a residential area in Hwasu-dong, Dong District, Incheon on Aug. 20. [YONHAP]

The seasonal term Cheoseo, which traditionally marks the retreat of summer heat, is fast approaching on Saturday — but signs of relief from the sweltering weather are nowhere to be seen.

The so-called “Cheoseo magic,” where heat usually fades after this point, appears absent this year, with temperatures forecast to soar past 36 degrees Celsius (96.8 degrees Fahrenheit) through the weekend.

Cheoseo is part of the 24 solar terms, first developed in ancient China, which divide the year into segments that reflect seasonal changes in climate, agriculture and natural phenomena. Marked by the sun’s position along the ecliptic, they guided traditional farming practices and daily life across East Asia, influencing everything from planting cycles to food customs and festivals, and is still used in talking of the weather today.

Hot and humid air continues to flow into the Korean Peninsula along the edge of the North Pacific High situated over waters south of Japan, according to the Korea Meteorological Administration (KMA) on Wednesday. With overnight temperatures remaining high, daytime heat is intensifying further.

This pattern is expected to persist through at least the middle of next week, as Korea remains under the influence of the high-pressure system's perimeter and continues to receive hot, humid air.

Wednesday’s daytime highs are projected to range from 30 to 36 degrees Celsius. Gwangju is forecast to reach 35 degrees Celsius, while Daegu is expected to hit 34 degrees Celsius. Daejeon, Ulsan and Busan will climb to 33 degrees Celsius, Seoul to 31 degrees Celsius and Incheon to 30 degrees Celsius.

As the heat wave continues, vacationers cool off at Gyeongpo Beach in Gangneung, Gangwon, on Aug. 18. [YONHAP]

Notably, Samcheok in Gangwon and the cities of Uljin, Pohang and Gyeongju in North Gyeongsang are forecast to see highs of up to 36 degrees Celsius. Regions east of the Baekdu Daegan mountain range are experiencing higher temperatures due to the foehn effect — a phenomenon in which dry air descending from the western slopes heats up as it travels down the mountains.

In its latest midrange forecast, the weather agency predicts that temperatures from Saturday — the day of Cheoseo — through the following 10 days will continue to be slightly above average, with morning lows between 23 and 27 degrees Celsius and daytime highs between 31 and 35 degrees Celsius.

On Wednesday, rainfall of 5 to 40 millimeters (0.19 to 1.57 inches) is expected in Jeju as a tropical depression — a precursor to a typhoon — moves from the sea south of Jeju toward Kyushu, Japan.

Unstable atmospheric conditions caused by the persistent heat will also bring scattered showers inland. Rainfall is expected to range from 5 to 20 millimeters in Incheon, northern Gyeonggi and Gangwon, and from 5 to 40 millimeters in Gwangju, South Jeolla, Busan, Ulsan and South Gyeongsang.

This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom. BY BAE JAE-SUNG [lim.jeongwon@joongang.co.kr]