Yangsan hits 40 C for fifth straight day in unprecedented heat record

Temperatures in Yangsan, South Gyeongsang Province, surpassed 40 degrees Celsius for the fifth consecutive day Sunday, setting an unprecedented record in South Korea's meteorological history. The threshold is also being crossed earlier in the day each time.

Yangsan's temperature exceeded 40 C for the fifth straight day Sunday. The crossing point has grown progressively earlier, with the city reaching 40.3 C at 11:47 a.m. — before noon for the first time.

The mercury then soared to 40.9 C by noon. The five-day streak of 40 C-plus readings since July 29 marks a record with no precedent in South Korea's weather observation history.

Among the 97 climate statistical observation stations managed by the Korea Meteorological Administration for temperature rankings, no single location had ever recorded a daily high of 40 C or above on two or more consecutive days before this Yangsan streak.

Even including automated weather station (AWS) data going back to 1973, the previous longest such streak was four consecutive days — Aug. 1 through Aug. 4, 2018 — when Sinnyeong in Yeongcheon, North Gyeongsang Province, recorded daily highs of 40 C or above during what was called the worst heat wave of the 21st century.

The time at which Yangsan first crosses 40 C each day has been creeping steadily earlier. On July 29 it was first reached at 3:26 p.m.; on July 30 at 1:10 p.m.; on July 31 at 12:36 p.m.; and on Saturday at 12:14 p.m.

Through Saturday the city had still been crossing into the 40s in the afternoon, but Sunday it did so before noon. The increasingly early crossings reflect a buildup of accumulated heat.

Peak solar radiation and the day's highest temperatures typically occur between 2 and 4 p.m. With Yangsan already surpassing 40 C well before that window, temperatures there could climb to record-breaking levels again Sunday.

If Sunday's high exceeds Saturday's and reaches 42 C, that too would be without precedent.

Saturday's reading of 41.6 C was already the highest temperature ever recorded in South Korea's 122-year meteorological history based on climate statistical observation stations. A reading of 42 C would set the all-time high even when AWS data are included.

In the AWS record, only three instances have logged higher temperatures than Saturday's Yangsan reading: 41.9 C in Jiwol-ri, Chowol-eup, Gwangju, Gyeonggi Province on Aug. 1, 2018; 41.8 C in Gangbuk-gu, Seoul, the same day; and 41.6 C in Geumsa-myeon, Yeoju, Gyeonggi Province on Aug. 4, 2024 — all falling short of 42 C.