Overnight temperatures in Seoul stayed above 25 C, marking the season's latest tropical night since meteorological observation began, the state weather agency said Tuesday.

The lowest nighttime temperature overnight in the capital city was 25.6 C at 6 a.m., another tropical night that refers to a phenomenon where temperatures do not drop below 25 C until 9 a.m., according to the Korea Meteorological Administration.

It marks the season's latest tropical night record in Seoul since record-keeping began in 1908, surpassing the previous record set on Sept. 8, 1935.

The southern island of Jeju experienced the tropical night phenomenon for a record 64 consecutive days.

On Tuesday, the daytime temperatures will rise up to 31-35 C, and the apparent temperatures will hover around 33 C, with the heat wave alert issued in most regions, including the greater Seoul area, the western part of Gangwon Province, and the southern regions.

The heat wave will peak on Wednesday before it weakens the following day with rain, but the heat is expected to linger until after next week's Chuseok holiday.

Rain of around 30 millimeters per hour is expected to fall in Jeju from Tuesday afternoon until Wednesday night, and most regions will see sporadic rain on Thursday, the KMA said. (Yonhap)