Cold air to trigger thunderstorms across northern Vietnam

According to the National Center for Hydro-Meteorological Forecasting, northern areas excluding Lai Chau and Dien Bien will experience thunderstorms from Thursday night through Friday.

Some 20-40 mm of rainfall is expected, with some locations getting in excess of 100 mm.

The thunderstorms could bring lightning, hail and strong gusts, possibly uprooting trees and causing damage to homes, transport infrastructure and public facilities.

Localized heavy rains could also cause flash floods in small rivers and streams, landslides in mountainous areas and flooding in low-lying zones.

Storm forecasts with an accuracy of 70-90% can typically be made only 30 minutes to three hours in advance.

Authorities have advised the public to closely monitor weather updates, limit outdoor activities during storms and secure their homes and property to minimize losses.

From April 17 northern Vietnam and Thanh Hoa are expected to turn cooler, ending the current heatwave.

American site AccuWeather forecasts temperatures in Hanoi dropping to 23-26 C by Friday from 26-34 C now.

Locations at altitudes of above 1,500 meters, such as Sa Pa in Lao Cai, will see temperatures of 15-21 C.

The central region, especially from Quang Tri to Da Nang and the eastern parts of Quang Ngai to Dak Lak, will remain warm with temperatures of 36-39 C and exceeding 39 C in some areas on Thursday.

But the region is expected to gradually become cooler from Friday.

A hailstorm with stones as large as a fist struck Bac Ha Commune in the northern province of Lao Cai early on Friday, lasting about 15-30 minutes and causing a series of damages to homes and crops.

Hailstones shatter the window of a car parked outdoors in Bac Ha Commune, Lao Cai Province, April 16, 2026. Photo by Bac Ha

The hailstones, measuring around 5-7 cm in diameter, shattered roofs, windows, and vehicles, while strong winds intensified the impact.

Residents described the storm as chaotic and frightening, with many taking shelter indoors as property and farmland were heavily affected. Authorities are assessing the damage and providing support, while weather officials warn of continued risks of thunderstorms, hail, and strong winds in northern Vietnam.