Heavy downpours are expected chiefly in the capital region on Thursday and Friday before blazing sunshine returns at the weekend.
But temperatures are not going down even at night, with hot air coming from China and Japan due to this year's third and fourth typhoons Chaba and Aere since early this week, the Korea Meteorological Administration said Wednesday.
Much of the country is experiencing sweltering tropical nights when the mercury refuses to drop below 25 degrees Celsius. Seoul has been hit by three tropical nights in a row and Jeju almost every day since June 25. Incheon has suffered its earliest tropical night on record in 20 years.
Thirty to 50 mm of torrential rain per hour will fall in the capital region and northern Gangwon Province from Thursday afternoon until early Friday morning, with the cumulative rainfall reaching 30 to 150 mm.
About 10 to 60 mm of rain will fall in Chungcheong, Jeolla, North Gyeongsang provinces for two days. But daytime highs will still reach 28 to 34 degrees on Thursday.
The weather will clear up on Saturday as the country comes under the influence of high air pressure until Sunday.
Heavy rains will fall again next Monday until July 15.