The National Centre for Hydro-Meteorological Forecasting said northern Vietnam recorded moderate to heavy rain on Monday, with some monitoring stations measuring more than 80mm, including 111.4mm in Quang Ninh and 105.4mm in Phu Tho.
From Monday evening through Tuesday night, rainfall across the region is forecast to range from 50mm to 120mm, with isolated areas receiving more than 250mm. The heavy rain is expected to ease from Tuesday.
Forecasters warned of flash floods, landslides and ground subsidence in mountainous areas and along small streams, particularly in Son La, Tuyen Quang, Thai Nguyen, Cao Bang and Bac Ninh.
The Central Highlands and southern Vietnam are forecast to receive 30-80mm of rain through Tuesday, with isolated totals exceeding 150mm, mainly in the afternoon and evening.
Scattered showers and thunderstorms are also expected in Thanh Hoa, Nghe An, Ha Tinh, Hue and the south-central coast on Monday night, with some areas likely to receive more than 70mm of rain.