Heat-related illnesses after traditional start of autumn nearly triple over 15 years

The annual average number of heat-related illness cases in late summer has nearly tripled over the past 15 years, data showed Saturday.

The National Disaster Management Research Institute, under the Ministry of the Interior and Safety, said the annual average number of heat-related illness cases from Ipchu, the traditional start of autumn, through the end of August was 215 from 2011 to 2015.

That figure rose to 658 between 2016 and 2020 and remained high, averaging 638 per year between 2021 and 2025.

This year, Ipchu fell on Friday, with temperatures in Seoul reaching 40 degrees Celsius (104 degrees Fahrenheit).

Heat-related deaths have also increased. An average of at least four people died from heat-related illnesses each year between 2016 and 2025, up from an annual average of 3.3 between 2012 and 2015.

In 2024, when a prolonged heat wave extended into late summer, 1,299 heat-related illness cases and 12 deaths were reported between Ipchu and the end of August.

Heat waves are expected to continue this year. The Korea Meteorological Administration forecast that nationwide daytime highs will range from 31 to 35 degrees Celsius through mid-August, above the seasonal average.

BY CHO JUNG-WOO   [cho.jungwoo1@joongang.co.kr]