Heat-wave days on the Korean Peninsula have risen 2.2 times over the last 10 years compared to the preceding decade [1].

This shift indicates an intensification of summer heat that threatens public health and infrastructure. As temperatures rise and humid nights become more frequent, the window for extreme heat exposure expands, placing greater strain on energy grids and urban populations.

The Korea Meteorological Administration (KMA) based its findings on a 53-year observation record [1]. The data reveals that tropical-night days have increased three times over the most recent 10-year period when compared to the previous 10-year block [1].

Beyond the frequency of extreme heat, the timing of the season has shifted. The start of the heat-wave season has moved up to 30 days earlier, with increases now appearing as early as June [1]. KMA officials said that the heat season now extends later into September [1].

"In the last 10 years, the start date of heat waves in our country has been advanced by up to about 30 days compared to the previous 10 years, and is increasing from June," Lee Won-gil, a KMA spokesperson, said [1].

The analysis highlights that these trends are particularly notable on Jeju Island and along the southern coast [1]. The KMA said this prolonged and intensified summer heat is due to ongoing climate change [1].

Reporter Jung Hye-yoon said that heat waves have more than doubled and tropical nights have surged three-fold within the decade [1].

“Heat-wave days on the Korean Peninsula have risen 2.2 times over the last 10 years”

The acceleration of both the onset and duration of extreme heat suggests that the Korean Peninsula is experiencing a fundamental shift in its seasonal climate patterns. By expanding the heat-wave window into June and September, the region faces a longer period of vulnerability to heat-related illnesses and increased electricity demand for cooling, necessitating updated urban planning and public health strategies.