Seoul tops 40 C as summer heat wave peaks; relief expected this weekend

Seoul's daytime temperature surpassed 40 degrees Celsius on Friday, marking the peak of this summer's extreme heat wave.

According to the Korea Meteorological Administration, an automated weather station (AWS) in Nowon-gu, Seoul, recorded 40.2 C at 3:28 p.m. Friday.

It was the first time an AWS reading in Seoul exceeded 40 C since Aug. 1, 2018, when a station in Gangbuk-gu recorded 41.8 C.

However, the Nowon-gu figure is an AWS reading and differs from Seoul's official representative temperature. AWS units monitor weather changes in narrow, localized areas, and readings can run higher depending on where the equipment is installed and the surrounding environment.

The Seoul Meteorological Observatory in Jongno-gu, which produces the city's official representative readings, recorded a high of 38.0 C on the same day.

Near-40 C heat was recorded across the country as well. Deokpung-dong in Hanam, Gyeonggi Province, briefly hit 40.7 C, while Gwangyang-eup in Gwangyang, South Jeolla Province, reached 40.2 C. Daytime temperatures soared to 39.8 C in Yeongwol, Gangwon Province, Geumsa-myeon in Yeoju, Gyeonggi Province, and Miryang, South Gyeongsang Province.

This summer's heat wave has also been record-breaking in duration. The KMA said the nationwide average number of heat wave days from June 1 through Thursday stood at 14.8, the fourth highest for that period since the national weather observation network was expanded in 1973.

Nighttime heat has been equally persistent. The nationwide average number of tropical nights over the same period reached 13.0, an all-time high.

The KMA issued a heat wave warning for all of Seoul effective 6 p.m. Friday. Such warnings are issued when the maximum apparent temperature stays at or above 35 C for two or more consecutive days, or when severe heat-related damage is anticipated.

The intensity of the heat wave is expected to ease somewhat starting this weekend. On Saturday, morning lows nationwide are forecast at 21 to 26 C and afternoon highs at 26 to 35 C. Similar conditions are expected Sunday.