SEOUL -- The highest-level heat wave warning was issued for all of Seoul for the first time Tuesday, as continued scorching heat is expected to push the capital's daytime temperature to 38 C.

The serious heat wave warning had been additionally issued for the northeastern and northwestern areas of Seoul as of 11 a.m., according to the Korea Meteorological Administration (KMA).

With serious heat wave warnings already issued for Seoul's southeastern and southwestern areas the previous day, all of Seoul came under the warning, which was first introduced to the nation's heat wave advisory system on June 1.

A serious heat wave warning is issued when the highest perceived temperature reaches 38 C or higher, or the maximum daily temperature reaches 39 C or higher, in an area where the highest perceived temperature is 35 C or higher for two or more consecutive days.

Visitors to Gwangmyeong Cave, just south of Seoul, cool off on Aug. 4, 2026, by walking through water mist sprayed from a cooling fog system. (Yonhap)
Visitors to Gwangmyeong Cave, just south of Seoul, cool off on Aug. 4, 2026, by walking through water mist sprayed from a cooling fog system. (Yonhap)

In many parts of Gyeonggi Province, which surrounds Seoul, serious heat wave warnings had taken effect as of 11 a.m. Tuesday. They included Osan, Hanam, western Yeoju, Goyang, Anseong, southern Paju and Yongin, the KMA said.

The highest-level heat wave warning was also issued for many regions in the southwestern Jeolla provinces, including Jeonju, Jangseong and northern Gokseong. It was declared in Boseong, Yeosu and Gwangyang on Saturday and Suncheon, southern Gokseong and eastern Gwangju on Monday, the agency noted.

As the heat wave has intensified, 18 additional heat-related illness cases were reported in Seoul on Monday, government data showed, bringing the city's cumulative total since May 15 to 185, including two deaths.

The Seoul metropolitan government said it was closely monitoring the rise in heat-related illnesses and has launched an all-out response, including watering roads and protecting vulnerable groups, like residents living in cramped housing.

The city government also designated about 4,000 locations, including community centers, senior citizen centers and welfare centers, as heat shelters.

The interior ministry also sent a text message to citizens on the day, urging them to refrain from going out and engaging in outdoor activities, drink plenty of water, rest in cool places and look after the safety of their families.

A photo of Seoul's Yeouido district captured by a thermal imaging camera on Aug. 3, 2026. Higher temperatures are displayed in red, while lower temperatures are in blue. (Yonhap)
A photo of Seoul's Yeouido district captured by a thermal imaging camera on Aug. 3, 2026. Higher temperatures are displayed in red, while lower temperatures are in blue. (Yonhap)
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