Rain that began in central regions Friday will spread nationwide overnight, with particularly heavy downpours expected in the provinces of South Chungcheong and North Jeolla early Saturday.

Forecasts call for 20 to 80 millimeters in both areas as well as 10 to 60 millimeters across Gangwon Province, the capital area and the Gyeongsang region, with more than 100 millimeters possible along the South Chungcheong coast and western North Jeolla.

Most regions will see precipitation taper off by Saturday morning, though showers will linger until Saturday night along the North Gyeongsang coast and until Sunday morning in Gangwon’s Yeongdong region.

Morning lows Saturday will range from 16 to 24 degrees Celsius, with temperatures in Seoul dipping down to 18 and those in Jeonju as low as 21, showing little change from Friday.

Daytime highs will reach 21 to 29 degrees, with Seoul set for a high of 24 Daegu for 27, an increase of one to three degrees.

Seas will be rough, with waves of two to three meters off the east and west coasts, and strong winds are expected along Jeju’s shores. Temperatures will drop further by Sunday morning and large day-night swings will set in.