According to the Vietnam Disaster and Dyke Management Authorities, storms and hail hit Hanoi and the provinces of Dien Bien, Lai Chau, Lao Cai, Tuyen Quang, Phu Tho and Thai Nguyen on Saturday evening.
As of 6.30 am on May 3, five people had been injured in Thai Nguyen Province, while 350 homes had their roofs blown off, including 309 in Thai Nguyen, 40 in Dien Bien and one in Lao Cai.
The storms also damaged 919 hectares of rice and crops in Dien Bien and Thai Nguyen, while six schools lost roofing and 12 power poles were toppled in Thai Nguyen.
Hailstones measuring up to 5-6 centimetres were reported in some areas, shattering car windows and damaging solar water heaters, solar panels and roofing materials.
The National Centre for Hydro-Meteorological Forecasting said a cold air mass would continue moving south on May 3, bringing further rain and thunderstorms to northern and north-central Vietnam.
Rainfall of 20-40 mm is forecast across northern Vietnam and Thanh Hoa through May 3, with isolated areas expected to receive more than 90 mm.
Forecasters warned of continued risks of tornadoes, lightning, hail and strong winds during thunderstorms.
Meanwhile, hot weather is expected to persist on May 3 in western mountainous areas from Nghe An to Da Nang and across southern Vietnam before easing from May 4.