Inland regions including Seoul, Gyeonggi and South Chungcheong provinces and areas near Incheon can expect some 10 to 40 millimeters of rain, while other regions can expect 5 to 30 mm.
The rain will stop during the daytime, but temperatures are forecast to drop sharply later in the day in most regions.
The weather agency also warned that in the afternoon strong winds will hit coastal and mountainous areas of Gangwon Province, urging people who own facilities such as greenhouses to take appropriate precautions.
Saturday will also bring some rain, and the chilly weather is expected to continue.
By Kim Jee-min (email@example.com)