This photo shows an electronic signboard displaying temperature at apartment complex in Seoul, Aug. 18. Yonhap

The current heat wave is expected to worsen even though a typhoon is approaching the country, the state weather agency said Monday.

Typhoon Jongdari, located over waters some 360 kilometers southwest of Japan's Okinawa at 3 a.m., is currently moving northward toward the west of the Korean Peninsula, according to the Korea Meteorological Administration (KMA).

By the time the typhoon reaches waters off the western city of Seosan on Wednesday, it is expected to have weakened to a low-pressure system.

But unlike previous typhoons that cooled heat waves, Jongdari is expected to bring more heat and worsen or prolong the current heat wave that has led to a record number of tropical nights with overnight temperatures staying 25 degrees Celsius or higher, the agency said.

The cities of Seoul and Busan also continued to set new records for the number of consecutive tropical nights with 29 and 25 days, respectively. Jeju Island reported its third-longest streak of tropical nights, with 35 days.

On Monday, the daily highs will hover around 31 to 36 degrees, with the apparent temperatures soaring up to about 35 degrees in most regions.

Some parts of the country will receive showers of around 5 to 30-40 millimeters, but it will only result in the humidity increasing, making it feel even hotter, the KMA said.

Sporadic rain is expected to begin falling in the southern regions and mountainous regions of Gangwon Province on Tuesday morning, and it will start raining in the central regions in the afternoon.

Jeju Island, along with the southeastern cities of Busan and Ulsan, is forecast to receive 30 to 80 millimeters of rain until Wednesday, and 20 to 60 millimeters of rain is expected in South Jeolla Province, North Gyeongsang Province and the easternmost islets of Dokdo.

The greater Seoul area, Gangwon Province and the five border islands in the West Sea will see a total of 10 to 40 millimeters of rain Tuesday and Wednesday, and 10 to 50 millimeters of rain is forecast in Chungcheong Province.

The rain will continue until Thursday.

Temperatures are expected to remain higher than normal at least until Aug. 29, according to the KMA. (Yonhap)