Seoul has posted its 37th tropical night this summer, the most in the city's history, the state weather agency said Saturday.

Seoul experienced yet another tropical night phenomenon overnight, setting the highest number in a single year since modern meteorological observation began in the city in 1907, the Korea Meteorological Administration (KMA) said.

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

The previous record was 36 days in 1994.

The southern resort island of Jeju also experienced its 40th consecutive tropical night, its second-longest streak on record.

The heat wave is expected to continue throughout Sunday morning in most regions, with apparent daily high temperatures hovering around 33-35 C, according to the KMA.