The South Korean government has implemented a tiered heat warning system based on perceived temperatures to protect citizens from extreme weather [1].

These measures are critical as the frequency and intensity of extreme heat increase due to the climate crisis. By establishing specific temperature thresholds, officials aim to provide clearer guidance to the public to prevent heat-related illnesses and deaths.

The system utilizes three distinct levels of alerts. A heat advisory is issued when the daily maximum perceived temperature reaches 33 °C or higher for more than two consecutive days [1]. If the temperature reaches 35 °C or higher for more than two consecutive days, the government issues a heat warning [1].

To address worsening climate conditions, the government introduced a third, higher tier called the "major heat warning" in 2024 [1]. This new classification allows the state to trigger more aggressive public health responses when temperatures exceed the standard warning levels.

Government agencies responsible for weather warnings manage the issuance of these alerts across the country. The area subjected to the major heat warning has expanded each year since its inception [1]. The shift toward using perceived temperature, which accounts for humidity, rather than simple air temperature provides a more accurate measure of how heat affects the human body.

Officials said the expanded system is a necessary adaptation to the evolving climate. The tiered approach ensures that resources and emergency protocols are scaled according to the actual risk posed to the population [1].

“The area under ‘major heat warning’ expanding each year.”

The addition of a 'major heat warning' tier reflects a systemic shift in how South Korea manages climate risk. By moving beyond traditional heat warnings and incorporating perceived temperature, the government is acknowledging that historical weather patterns are no longer sufficient benchmarks for public safety. This evolution suggests that extreme heat is becoming a permanent, intensifying feature of the region's climate, requiring more granular emergency response levels.