Amid the prolonged heat wave, Seoul experienced 23 tropical nights in July, the highest tally for the month since the nation started weather observations 117 years ago.

According to the Korea Meteorological Administration, the overnight low in Seoul recorded 27-point-eight degrees Celsius between 6 p.m. Thursday and 9 a.m. Friday, well above the 25-degree threshold that defines a tropical night.

The sweltering night brought the total for July to 23, setting a fresh record for the city just a day after it broke the previous record of 21 tropical nights in July 1994. 

Incheon, Daejeon, Busan and Jeju Island also experienced a tropical night. 

The weather agency forecast that Seoul and the surrounding area will continue to experience tropical nights through August 10.