A wave of low pressure brought torrential rain central and southern South Korea from Sunday night into Monday.
Rainfall averaged 50-100 mm (2-4 in) across the southern half of South Korea with isolated amounts over 250 mm (10 in).
Some of the heaviest rain was reported around Busan and Changwon where widespread flooding has been reported.
At least one person has died with widespread evacuations and rescues reported across the region according to Bloomberg.
South Korea's Minister of Security and Public Administration ordered schools to adjust their schedules to ensure the safety of students due to the flooding.
Flooding reached the third floor of a middle school forcing 400 students onto the roof where they were later rescued.
Many automobiles, including buses, were swept away by raging flood waters across the region.
Also, a senior citizen center was severely damaged after the roof collapsed during the heavy rainfall.
The heavy rain and flooding also impacted a nuclear power plant. Korea Hydro & Nuclear Power Co. halted operations at Kori No. 2 nuclear reactor water entered the facility.
The heaviest rain has ended across South Korea as the low pressure system is now moving into Japan where locally heavy rainfall is expected across northern Honshu through Tuesday.
Scattered showers will continue across South Korea through Wednesday, but no further heavy rain is expected.