Cao Bang, Thai Nguyen, Lang Son, and Bac Ninh are experiencing historic floods with widespread inundation and urgent cries for help. Forecasts suggest that this extreme weather event will continue for another 3–4 days, particularly in Thai Nguyen and Bac Ninh.

On the afternoon of October 8, Le Ngoc Quyen, Deputy Director of the Northern Meteorological and Hydrological Station under the Ministry of Natural Resources and Environment, provided details on the extraordinary rainfall and flooding affecting the Viet Bac region and the Red River Delta.

The cause of the floods and widespread inundation

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Ly Village in Yen Binh Commune, Lang Son Province, was completely submerged by floodwaters. Photo: Quynh Anh - Roi

According to Quyen, the tropical storm Matmo (Typhoon No. 11) made landfall in Fangcheng, Guangxi Province, China on the morning of October 6 before weakening into a low-pressure system that moved west-northwest. By nightfall, its center was located over the mountainous northern provinces of Vietnam.

From the night of October 6 through the afternoon of October 7, a strong southeasterly wind at altitudes up to 5,000 meters combined with a southwesterly flow from the Bay of Bengal to form a convergence zone over the northern mountainous and midland regions, triggering extremely heavy rainfall across Cao Bang, Thai Nguyen, and Lang Son.

Rainfall data recorded over 36 hours (from 7:00 AM on October 6 to 7:00 PM on October 7) showed staggering levels in Thai Nguyen, ranging from 200–400 mm. Some areas saw even more, including Dong Hy with 596 mm, Nam Hoa with 554 mm, and Phan Dinh Phung Ward with 514 mm.

In Cao Bang, rainfall averaged 100–200 mm, with localized areas like Xuan Truong receiving 293 mm, Nguyen Binh 273 mm, and Minh Tam 266 mm. Lang Son saw similar patterns, with totals in Yen Binh reaching 334 mm, Tan Tri 290 mm, and Thien Tan 279 mm.

“In just 36 hours, rainfall surpassed the monthly average for October recorded over many years,” Quyen explained. “The combination of intense short-term rain, sloped terrain descending from north to south, and narrow, winding rivers led to slow drainage. As water rushed downstream faster than it could exit lower regions, severe flooding and massive inundation occurred.”

Thai Nguyen, Lang Son, Bac Ninh: Floodwaters break historic records

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Le Ngoc Quyen, Deputy Director of the Northern Meteorological and Hydrological Station, explains the causes of the severe floods. Photo: National Center for Hydro-Meteorological Forecasting

Relentless rainfall has caused river levels across the North to rise rapidly, surpassing historic flood levels in several locations. Quyen reported that rivers including the Gam, Giang, Cau, Thuong, and Trung in Tuyen Quang, Cao Bang, Thai Nguyen, Lang Son, and Bac Ninh have seen water levels exceed level 3 flood warnings.

Specifically, floodwaters at Gia Bay station on the Cau River in Thai Nguyen reached 29.9 meters - 2.9 meters above warning level 3 and 1.09 meters above the historic record.

At Huu Lung station on the Trung River in Lang Son, levels reached 24.31 meters - 5.31 meters above warning level 3 and 1.77 meters higher than the previous record.

At Cau Son station on the Thuong River in Bac Ninh, the level was 17.97 meters - 1.97 meters above warning level 3 and 0.36 meters above the historic mark.

Currently, most rivers are receding, although levels in Bac Ninh continue to rise and are expected to peak between tonight and the morning of October 9. The Cau River is forecast to exceed flood warning level 3 by about 1 meter, while the Thuong River may rise 1.5–2 meters above level 3 and surpass historical highs by 0.3–0.5 meters. The Trung River in Lang Son is also rising slowly and is expected to crest later today.

Flood and rainfall outlook

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In Soi Coc hamlet (Trung Thanh Ward, Thai Nguyen), rising river levels flooded numerous neighborhoods, affecting around 400 households. Photo: Bao Khanh

“Our forecast indicates that over the next few days, the weather in northern Vietnam will improve, with sunshine and only scattered showers and thunderstorms in isolated areas,” Quyen stated.

However, due to the slow recession of water levels in rivers, flooding is expected to persist, especially in Thai Nguyen and Bac Ninh, for another 3–4 days or longer in some locations.

Regional flood impacts by province:

Thai Nguyen: Widespread and deep flooding is expected to last 3–4 days or longer in several areas, including: Phan Dinh Phung, Gia Sang, Tich Luong, Linh Son, Quan Trieu, Phu Luong, Quang Son, Dong Hy, An Khanh, Yen Trach, La Hien, Nghinh Tuong, Nam Hoa, Trung Hoi, Van Han, Phu Dinh, Dai Phuc, Than Sa, Binh Thanh, Trai Cau, Lam Vy, Dan Tien, Van Xuan, Pho Yen, Diem Thuy, Phu Binh, Kha Son, Dai Tu, Phu Lac, Nam Cuong, Ba Be, Cho Ra, Hiep Luc, Na Ri, Van Lang, Cuong Loi, Con Minh, Xuan Duong, Bac Kan, Yen Binh, and Cho Moi.

Bac Ninh: Flooding is expected to persist for 3–4 days or longer in many areas such as Tam Tien, Xuan Luong, Yen The, My Thai,

Dong Ky, Lang Giang, Kep Commune, Tien Luc, Tan Yen, Tien Phong, Bac Giang, Yen Dung, Viet Yen, Hop Thinh, Xuan Cam, Tam Giang, Yen Trung, Tam Da, Nenh, Yen Dung, and Canh Thuy.

Cao Bang: Widespread flooding will last 1–2 days or longer in riverside areas including Hoa An Commune, Thuc Phan Ward, Nung Chi Cao, Tan Giang, and Phuc Hoa Commune.

Lang Son: Floods will continue for 2–3 days or more in areas including Yen Binh, Van Nham, Huu Lung, Tuan Son, and Cai Kinh.

Bao Anh