Downpours are forecast nationwide starting Wednesday afternoon.

According to the Korea Meteorological Administration, monsoon rains are expected in the Chungcheong region and the southern parts of Gyeonggi and Gangwon provinces, with hourly precipitation of up to 50 millimeters between late Wednesday and early Thursday.

A maximum of 150 millimeters are projected for the capital area and the Chungcheong region through Thursday, with up to 100 millimeters in Gangwon and North Jeolla provinces, and up to 80 millimeters in Busan, Ulsan and the Gyeongsang region.

The deluge is likely to affect the southern resort island of Jeju and the country’s southern areas starting Thursday afternoon.

The heat wave is expected to return Sunday in the wake of an expanded high-pressure system from the North Pacific, with sporadic showers amid atmospheric instability.