For first time in 12 years, midsummer cold front to bring downpours to northern Vietnam

The National Center for Hydro-Meteorological Forecasting said June cold fronts, once a near-annual feature of northern Vietnam, have grown steadily rarer over the past four decades. The agency logged 25 of them between 1979 and 2025, about 0.53 a year.

Since 1991 that count fell to just seven across 35 years. From 2014 through 2025, not a single one was recorded.

Nguyen Van Huong, who heads the center’s weather forecasting division, attributed the disappearance to climate change and global warming.

The returning front will reach the northern mountains on the afternoon and evening of June 8 before spreading across the northeast, parts of the northwest and north-central Vietnam.

Combined with a high-level wind convergence zone, the system will dump widespread moderate to very heavy rain from the evening of June 8 through June 9.

The northwest and the northern reaches of Phu Tho and Tuyen Quang will face 80-160 mm, with some spots exceeding 250 mm. Rainfall in Thanh Hoa and Nghe An is forecast at 50-100 mm, locally above 150 mm. Forecasters warned of cloudbursts topping 100 mm in three hours, along with thunderstorms, lightning, hail and strong gusts. In the northwest mountains and northern Phu Tho and Tuyen Quang, the risk of flash floods and landslides is rated high.

Temperatures in the northeast and Thanh Hoa will drop 5-7 C on June 9, with daytime highs staying below 31 C and lows of 22-25 C, dipping under 21 C in the mountains. In Hanoi, heavy rain and thunderstorms will run from the evening of June 8 into the next morning, with isolated downpours of 100 mm or more in 24 hours and lows of 23-25 C, 4-5 C cooler than recent days.

Offshore, the northern Gulf of Tonkin will see waves of 1.5-2.5 meter, which could disrupt maritime activity.

The cold air also ends a stretch of extreme heat in central Vietnam that had run since May 31. From June 9 the hot weather will retreat to the strip from Hue south to eastern Dak Lak Province, and by June 10 the heatwave will largely break.

With heavy rain, flash floods and landslides threatening mountainous areas, the National Civil Defense Steering Committee has ordered northern provinces and cities, along with Thanh Hoa and Nghe An, to ready response measures, review zones at high risk of flooding and landslides, and prepare to evacuate residents if needed.