Traffic moves along a street in Hà Nội on the morning of September 26. The cold air mass is forecast to bring scattered thunderstorms in the coming days. — Photo laodong.vn

HÀ NỘI — A weak cold air mass is forecast to reach northern Việt Nam from Wednesday night, ending a series of hot days and bringing scattered thunderstorms, the national weather forecaster said.

The north has been sweltering in humid autumn heat, with temperatures reaching 35 to 36 degrees Celsius in parts of the northwest. The National Centre for Hydro-Meteorological Forecasting said those conditions would persist until about September 29.

The incoming cold air is expected to lower temperatures by about 3 to 4 degrees, bringing highs across the north down to 30 to 32 degrees in the days that follow. Higher mountain areas could turn chilly, with lows dipping below 20 degrees.

Showers and thunderstorms are also expected across the north from Wednesday night. The centre said they would come in short bursts over narrow areas, with widespread, prolonged heavy rain unlikely.

Further south, the north-central provinces of Thanh Hóa, Nghệ An and Hà Tĩnh will see showers and thunderstorms, with heavy rain in some places, as the cold air meets the region's windward terrain.

Meanwhile, thunderstorms have been hitting central and southern Việt Nam, from Huế to Khánh Hòa. Several stations recorded more than 50 millimetres of rain between noon and 3pm on September 27, including 77.8 millimetres in the southern province of Cà Mau.

Rain in those provinces and cities is forecast to taper off from Monday. — VN