Northern Vietnam to experience its first cold spell, with temperatures dropping below 23C

Northern Vietnam is set to experience its first cold air spell of the 2026-27 cold season, with temperatures in some midland and mountainous areas forecast to fall below 23C.

The National Center for Hydro-Meteorological Forecasting said a cold air mass currently moving through China could reach northern provinces between September 9 and 11. The spell is expected to be relatively weak, but rain, showers and thunderstorms may occur from the night of September 9 to 10 before easing quickly.

Between September 10 and 12, daytime temperatures in the north are expected to fall below 33C. Overnight and early-morning temperatures could drop below 25C, while Hanoi is forecast to range from about 24C to 31C. The weather service said the cold air would arrive three to five days earlier than the long-term average for the first cold spell, which typically occurs between September 12 and October 4.

The earliest first cold spell previously recorded occurred on August 16, 2003, according to the weather service. From September 9 to 11, northeast winds in the northern Gulf of Tonkin could reach force 5, occasionally force 6, with waves 2 to 3 metres high and rough seas.

The forecast also includes scattered thunderstorms in central and southern Vietnam. Officials warned that thunderstorms could bring tornadoes, lightning, hail and strong gusts, damaging crops, trees, homes, transport works and infrastructure. Heavy rain could also trigger flash floods, landslides and flooding in low-lying areas.