Tropical nights are forecast in the inland regions and areas along the east coast amid the prolonged heat wave.

According to the Korea Meteorological Administration(KMA), fog with a visibility range of less than one kilometer is expected overnight along the west coast, south coast and in the inland regions.

Rain is in the forecast for the capital area and eastern Gangwon Province between Friday morning and evening - up to five millimeters in Seoul and the southern part of Gyeonggi Province, and up to 20 millimeters elsewhere. 

Morning lows on Friday are expected to range between 21 and 28 degrees Celsius, and daytime highs to stand between 30 and 36 degrees.