22nd tropical nights recorded most ever for July in the Korean capital

A water show plays at the Banpo Bridge over the Hangang River on Tuesday night. (Yonhap)
A water show plays at the Banpo Bridge over the Hangang River on Tuesday night. (Yonhap)

Temperatures in Seoul never dipped below 29.3 degrees Celsius between Wednesday night and Thursday morning, which meant the city had set a new record: the highest number of tropical nights in July since modern weather observations began over a century ago.

According to the Korea Meteorological Administration, the nation's most populated city has now experienced 22 tropical nights this month, breaking the previous record of 21 set in July 1994.

A tropical night is a meteorological term referring to when the temperature stays above 25 degrees from 6:01 p.m. to 9 a.m. the next day.

As of Thursday morning, the KMA is projecting Seoul's temperature to dip to as low as 27 degrees Celsius at around 6 a.m. Friday, which means the city would likely have its 23rd tropical night for July.

2025 already shaping up to be one of hottest summers ever

While South Korea saw several heat-related records broken this month, August is usually the hottest month of the season. As such, expectations that the country is heading into the worst heat wave in recorded history are growing.

The first-ever temperature measurement for the country took place in October of 1907, and the weather observation for the summer started in the following summer of 1908.

Years 1994 and 2018 are considered among the hottest summers ever in Korea. The year 1994 is considered to have had the worst heat wave of the 20th century in Korea, with Seoul's temperature climbing to as high as 38.4 degrees to set the then-record.

The highest-ever temperature in the Korean Peninsula was recorded on Aug. 1 of 2018, when the rural county of Hongcheon-gun, Gangwon Province, heated up to 41 degrees. Seoul also set a new record by marking 39.6 degrees on the same day.

In terms of longevity, 2024 set the record in Seoul, Busan, Incheon, Jeju and other regions across the country for the longest streaks of tropical nights. Tropical nights persisted for 34 straight days in the capital, while the southernmost island region of Jeju had a whopping 47 straight tropical nights starting from July 15.

With global temperatures rising and records continuing to be broken, there is a growing concern that this summer may be the hottest one yet. Experts like Professor Kim Baek-min of Pukyong National University have said that extreme heat is no longer a temporary phenomenon, but something that will likely keep occurring.

People rest in the shaded forest near the beach in Gangneung, Gangwon Province, Monday morning. (Yonhap)
People rest in the shaded forest near the beach in Gangneung, Gangwon Province, Monday morning. (Yonhap)

minsikyoon@heraldcorp.com