Pavement temperatures at Gwanghwamun Square in Seoul reached approximately 40°C this week as a prolonged heat wave gripped the city [1].
The extreme surface heat combined with high humidity creates a dangerous environment for pedestrians and tourists. When urban surfaces absorb and radiate heat, it exacerbates the heat-island effect, increasing the risk of heat-related illnesses for those spending time in open public spaces.
According to reporting by YTN, the ambient air temperature was recorded at 33°C [1]. However, the ground surface remained significantly hotter, reaching the 40°C mark [1]. This disparity is further intensified by a relative humidity level of approximately 60% [1].
Visitors at the square described the conditions as oppressive. One citizen said the heat was so intense that it felt like it was "hard to breathe" [1].
YTN reporter Jung Young-soo, who conducted on-site reporting for seven hours starting at 8:30 a.m., described the physical toll of the environment [1]. "The heat rising from the ground makes me sweat and feel thirsty even while standing still," Jung said [1].
The combination of high humidity and radiating surface heat prevents the body from cooling efficiently through sweat evaporation. This creates a localized environment where the perceived temperature is much higher than the official air temperature recorded by weather stations.
“The pavement of Gwanghwamun Square reached approximately 40°C.”
This situation highlights the danger of the urban heat-island effect, where concrete and asphalt absorb solar radiation and release it slowly. When surface temperatures significantly exceed air temperatures during high-humidity events, public squares can become hazardous zones, necessitating urban planning interventions such as increased canopy cover, or cooling pavements, to protect public health.
