Seoul saw its 32nd consecutive tropical night between Wednesday and Thursday, extending the record for the longest streak of tropical nights in the city's modern history.  

A tropical night is defined as a night when the minimum temperature stays above 25 degrees Celsius from 6 p.m. to 9 a.m. the next day. 

The southern port city of Busan also experienced a tropical night between Wednesday and Thursday, just a day after breaking a 26-day streak. 

As of 8 a.m. Thursday, temperatures had already climbed to nearly 30 degrees Celsius in major cities including Seoul, Incheon, Daejeon and Ulsan. 

Afternoon highs on Thursday are expected to range from 30 to 36 degrees, with perceived temperatures likely to rise to 33 to 35 degrees due to high humidity. 

Rain is forecast nationwide in the afternoon, with showers likely to continue in parts of the nation until Friday morning.