Northern region is the epicentre of the heatwave, with record-breaking temperatures for August. — VNA/VNS Photo

HÀ NỘI — A powerful combination of weather systems has sent temperatures soaring across northern Việt Nam, with parts of the Red River Delta experiencing the highest August heat on record, according to the National Centre for Hydro-Meteorological Forecasting.

On August 3 and 4, widespread hot weather affected the North, parts of the central localities from Thanh Hóa Province to Huế City and the southern coast. 

The Red River Delta was the epicentre, with Hà Nội's Láng Station hitting 39.7 degree Celsius and Phủ Lý, Ninh Bình Province reaching 39.3C, both setting new August temperature records.

Meteorologist Nguyễn Văn Hưởng identified three key causes behind the extreme heat. A strong western low-pressure system pushed hot, dry air into northern region. 

Upper-level divergence winds at 1,500–3,000m led to clear skies and prolonged sunlight. Meanwhile, foehn winds from the west to southwest, blowing from Thanh Hóa to the lowlands, further intensified the heat and lowered humidity.

This rare overlap of high-pressure systems and dry winds created a prolonged, intense heatwave with low humidity levels, down to 47–52 per cent in Hà Nội by Monday afternoon, resulting in especially harsh, dry conditions.

A low-pressure trough is expected to bring widespread rainfall across northern region starting from Tuesday, gradually easing the heat. Daytime temperatures will fall to around 35–36C, mainly in lowland areas.

By Wednesday, increased rainfall will neutralise the effects of the hot low-pressure system and foehn winds, bringing an end to the current heatwave.

The national weather agency has warned that while hot weather may persist in some northern and central areas on Tuesday, with highs over 38C, evening heavy showers and thunderstorms could bring strong winds, hail, lightning and flash floods, particularly in mountainous regions. — VNS