Seoul, Sep 11 (IANS): An unprecedented autumn heat wave in South Korea is set to reach its peak on Wednesday, the state weather agency said, as the daytime high is forecast to rise to a record 35 degrees Celsius in Seoul amid a heat wave advisory issued for almost all regions of the country.

The Korea Meteorological Administration (KMA) said overnight temperatures in the capital again stayed above 25 degrees Celsius on Tuesday, marking the latest tropical night since modern meteorological observation began, Yonhap news agency reported.

The southern island of Jeju experienced the tropical night phenomenon for a record 65 consecutive days.

The maximum daily temperature in Seoul is expected to soar to 35 degrees Celsius, which will set a new record for the highest temperature of September, the KMA said.

The agency issued a heat wave advisory for almost all regions, excluding east coast areas of Gangwon Province, inland areas of North Gyeongsang Province, and Jeju's Mount Halla.

A heat wave advisory is issued when the highest apparent temperature is expected to be 33 degrees Celsius or higher for two or more consecutive days.

The KMA said the ongoing heat wave is expected to abate temporarily for the rest of the week, as rain is expected nationwide on Thursday and in the capital and northern Gangwon regions on Friday.

The number of heat-related patients in South Korea has exceeded 3,000 this year, according to the Korea Disease Control and Prevention Agency (KDCA), said in August end.

The agency said that extreme heat has also claimed 28 lives in the country, Yonhap reported.

It marks the second-largest tally on record, with the highest number of heat-related patients reported in 2018 when 4,526 cases were recorded.