Starting this summer, a "heat wave critical warning," one step higher than a "heat wave warning," will be introduced. It is intended to be issued when the day's high reaches 39℃ or higher.
The Korea Meteorological Administration announced on the 12th its "2026 summer season key disaster-prevention weather measures," centered on these points.
The current heat wave advisory system has two levels: a heat wave advisory (when the daily maximum heat index of 33℃ is expected to persist for two or more days) and a heat wave warning (when the daily maximum heat index of 35℃ is expected to persist for two or more days).
The Korea Meteorological Administration will add a heat wave critical warning as the highest alert level. A heat wave critical warning means that due to unusual heat, the risk of serious harm, including death, is markedly high for the entire population, including healthy people. It is issued when the daily maximum heat index is expected to be 38℃ or higher or when the day's high is expected to be 39℃ or higher.
A tropical night advisory will also be newly introduced. Going forward, if the nighttime low is expected to be 25℃ or higher in areas at or above the heat wave advisory level, a tropical night advisory will be issued. However, considering local topography, in large cities with populations of 500,000 or more and in coastal and island areas, the threshold will be 26℃, and on Jeju Island it will be 27℃ for issuing a tropical night advisory.
Starting this month, emergency disaster text alerts will be sent for catastrophic downpours with an hourly accumulated rainfall of about 100 mm. Emergency alerts will also be sent when hourly accumulated rainfall is 85 mm and 15-minute accumulated rainfall is 25 mm. To help the public recognize and prepare for heavy rain, information on the possibility of heavy rain will be provided two to three days in advance.
The Korea Meteorological Administration said it expects this will help protect public safety by prompting immediate evacuation and response actions.