The national weather agency said the northeast, parts of Lao Cai and Phu Tho provinces, along with Thanh Hoa and Nghe An, could see rainfall of 50-120 mm, with some areas receiving more than 250 mm.
Rainfall overnight already exceeded 100 mm in several localities, including Tuyen Quang, Thanh Hoa and Phu Tho provinces.
Forecasters warned of intense downpours exceeding 100 mm within three hours in some areas, raising the risk of flash floods and landslides in mountainous regions.
Northern localities are expected to remain relatively cool due to the rain, with temperatures ranging between 24 and 33 degrees Celsius.
