The National Centre for Hydro-Meteorological Forecasting said northern mountainous and midland areas would see scattered showers and thunderstorms through May 11, with rainfall of 10-30 mm and some areas exceeding 90 mm.
Authorities warned of risks including whirlwinds, lightning, hail and strong winds during thunderstorms.
Southern Vietnam is forecast to see sunny conditions and hot weather in some areas, particularly in the southeastern region, while scattered showers and thunderstorms are expected in the late afternoon and evening from May 10.
The weather agency said northern Vietnam could experience localised heat from around May 12, while widespread heatwaves may develop across the north-central and central regions from around May 13.
The Central Highlands and southern regions are also forecast to see scattered showers and thunderstorms from around May 16.
