Much rain is in store for the nation from Monday night. 

According to the Korea Meteorological Administration(KMA) on Monday, rain began to hit Jeju Island and coastal areas of the southeastern South Jeolla Province between 4 p.m. and 6 p.m. and expanded to affect the Jeolla regions and Chungcheong provinces. 

The entire nation is forecast to be soaked by the spring rain from about 9 p.m., the weather agency said. 

Precipitation was anticipated to stop in most regions by Tuesday afternoon, though the southern regions were predicted to see significant rainfall within a short span of the time. The areas of South Jeolla, South Gyeongsang and Jeju are expected to see upwards of over 50 millimeters of rain per hour between Monday night and Tuesday morning. 

For some mountainous areas on Jeju, more than 300 millimeters were forecast, while over 150 millimeters were in store for southern Jeju and southern coastal areas of the mainland.