According to the National Center for Hydro-Meteorological Forecasting, the incoming cold air will compress a low-pressure trough, triggering widespread rain across most of the northern region, except Lai Chau and Dien Bien, as well as Thanh Hoa.

Rainfall is expected to range from 20-40mm, with some areas potentially exceeding 100mm. From April 17, the north will turn cooler.

Meteorologists caution that this transitional period between seasons often brings hazardous weather. Following prolonged heat, thunderstorms may be accompanied by whirlwinds, lightning, hail, and strong gusts, posing risks to both people and property.

Localized heavy rain could also trigger flash floods in small rivers and streams, landslides on steep slopes, and urban flooding in low-lying areas.

Before the cold air arrives, heat will continue to dominate across much of the country. Over the next two days, the northwest and parts of the north-central highlands will see temperatures of 35-36°C, with some areas exceeding 36°C and low humidity levels.

From Nghe An to Hue, extreme heat will persist, with temperatures ranging from 37-39°C and in some places surpassing 39°C. Da Nang and eastern areas from Quang Ngai to Dak Lak will also experience intense heat, with highs of 36-38°C.

In the northeast, Thanh Hoa, and the southern region, localized heat above 35°C is expected.

From April 17, widespread heat in the north and north-central region is forecast to end as thunderstorms and cooler conditions take hold. Other regions are also expected to gradually cool.

Looking further ahead, northern Vietnam and areas from Thanh Hoa to Ha Tinh will experience scattered showers and thunderstorms from the night of April 16-17 and again between April 18-20, with localized heavy rain.

In Hanoi, rainfall is expected to increase gradually between April 15 and 21. Thunderstorms over the weekend are forecast to bring temperatures down to around 29°C, followed by several days of milder conditions at 30-31°C before another warming trend sets in.

Elsewhere, from April 16 to 22, Da Nang and eastern areas from Quang Ngai to Dak Lak will see reduced heat, with scattered evening and nighttime showers.

The central highlands and southern regions will continue to experience hot days with occasional localized heat, while showers and thunderstorms are likely in the late afternoon and evening. Severe weather such as lightning, hail, and strong winds remains a possibility during storms.

Bao Anh