The number of tropical nights reached 20.2 days this year, outnumbering 16.8 days in 1994 and 16.7 days in 2018 since the Korea Meteorological Administration (KMA) began compiling the data in 1973, Yonhap news agency reported, citing the KMA.

A tropical night refers to a phenomenon when the nighttime temperatures stay above 25 C from 6:01 p.m. to 9 a.m. the following day.

The number of tropical nights in August reached 11.3 days, the first double-digit record for August, it added.

The number of days with daytime highs exceeding 33 C also came in at 23.2 days, the third highest since 31 days in 2018 and 29.6 days in 1994.

The KMA said that the peak of this year's heat wave has passed but high temperatures will likely continue into September, especially in the first 10 days of the month.

The number of heat-related patients has been steadily growing, as scorching heat continued to sweep across the nation when the government began monitoring cases for the year, according to the Korea Disease Control and Prevention Agency.

Extreme heat has also claimed 28 lives till August, the agency said