'Too hot' vs 'Too cold': 75% of subway complaints temperature-related

A Seoul subway platform. (Yonhap)

A total of 283,972 complaints related to heating or air-conditioning on subway trains have been issued by Seoul Subway passengers this year, making up 75.5 percent of all complaints in the first five months of 2025.

Seoul Metro, the main operator of the city's subway systems, said that over 110,000 temperature-related complaints were issued to the customer center in the month of May alone.

Under Ministry of Environment guidelines, Subway cars are maintained at a designated temperature of around 24 degrees Celsius in the summer and 18 degrees Celsius in winter. However, the temperature of each car tends to spike during rush hours when trains are jam-packed, due to passengers' body temperature.

As such, heat-related complaints tended to peak at the commuting hours of 7-9 a.m. and 6-8 p.m., with 623,969 saying it was too hot and 35,538 saying it was too cold.

Seoul Metro's Ttota Subway application gives real-time information on how packed each subway car is.

Subway trains also have designated cars with weaker air conditioning, which maintain temperatures at around 25 C in the summer. These are the fourth and seventh cars of trains on Subway Line Nos. 1, 3 and 4; the fourth and fifth cars of trains on Subway Line Nos. Lines 5, 6, 7; and the third and fourth cars for trains on Line No. 8.

Line No. 2 does not operate such cars.