From October 15 to November 3, Hue experienced five consecutive heavy rainfall events, resulting in three particularly severe floods along local rivers.

On November 3, the Bo River in Phu Oc reached 5.31 meters, surpassing warning level 3 by 0.81 meters, breaking all previous records.

This marked the third time in just over a week that the Bo River set a new record, after reaching 5.25 meters on October 27 and 5.27 meters on October 29 - both exceeding the previous high in 2020 of 5.24 meters.

Of note, Bach Ma recorded 1,739 mm of rain in a single day (from 7 p.m. on October 26 to 7 p.m. on October 27), nearly equaling Vietnam’s annual average rainfall (1,400–2,400 mm). This figure ranks second globally, behind only a rain event in the Indian Ocean in January 1966.

Rising river levels led to severe flooding across many streets and residential areas in Hue. Initial reports from the third flood show over 28,000 homes submerged, with water depths ranging from 0.5 to 1 meter.

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The Hue Imperial Citadel area surrounded by floodwaters on the afternoon of October 29. Photo: Nguyen Phong

Significantly, heavy rains also inundated many historical sites in Hue, including the Imperial City, Minh Mang Mausoleum, Gia Long Mausoleum, Tu Duc Mausoleum, and Dong Khanh Mausoleum, raising concerns about the preservation of these cultural landmarks.

The Meteorological and Hydrological Administration (Ministry of Agriculture and Environment) cited expert Nguyen Viet, former director of the Thua Thien Hue Hydro-Meteorological Station and current official at the National Hydrometeorological Administration, who offered insights into Hue’s flood situation.

He explained that while floods may have occurred historically, the absence of comprehensive data makes comparisons difficult. According to the World Meteorological Organization (WMO), a standard 30-year period is required to study climate patterns.

Based on recorded observations, Hue has experienced major floods in the past. For instance, in August 1811 (Year of the Goat), a major storm and flood submerged the royal capital by over 8 meters, also impacting provinces such as Quang Tri, Quang Binh, Quang Nam, and Quang Ngai.

That 1811 flood caused the royal citadel to be submerged by 3.36 meters, even breaking through the Tu Hien gate. In 1818, the capital was under 4.2 meters of floodwater. August 1820 and August 1843 also saw floods ranging from 3 to 4 meters. The 1941–1942 floods led to the collapse of 700 homes in the capital.

More recent data include: the September 20–26, 1953 flood with 795 mm of rainfall; the October 1–8, 1969 flood with 1,426 mm; the October 16–20, 1975 event with 1,445 mm; the October 28–November 1, 1983 rainstorm totaling 1,262 mm; and the November 1–6, 1999 flood with a staggering 2,288 mm.

Causes of heavy rain

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Cars parked on a bridge to avoid floodwaters during the third flood event, early November 2025. Photo: Nguyen Phong

Nguyen Viet identified several contributing weather patterns in the Central Highlands and southern regions that lead to flooding. These include intense southwest monsoons; tropical storms or depressions; tropical systems combined with cold air; cold air interacting with intertropical convergence zones (from 10–13° N); and cold air merging with upper-eastern winds or other disturbances.

He emphasized that when two or more weather systems combine with high intensity, it often results in extreme rainfall and unusually large floods.

"Hue has always been vulnerable to flooding due to its geography. Even before urbanization and with greater forest cover, floods were common. While modern development influences the situation, it's not the sole factor," Viet noted.

Associate Professor Dr. Mai Van Khiem, Director of the National Center for Hydrometeorological Forecasting, also weighed in on the recent floods.

He attributed the intense rainfall to a combination of low-level cold air, a northward-shifting intertropical convergence zone, and moist easterly winds at 1,500–5,000 meters altitude.

"This weather combination is typical of central Vietnam’s extreme rain events. Major and prolonged downpours almost always stem from these systems," Khiem explained.

According to Nguyen Viet, given current forecasting capabilities, the WMO recommends impact-based forecasting and proactive risk alerts.

With early warnings, residents are encouraged to monitor updates regularly to be ready for possible flooding and better adapt to climate change.

The Meteorological and Hydrological Administration warns that over the next 10 days, both mainland and offshore areas, including the East Sea, are likely to experience hazardous weather patterns.

Of particular concern is the tropical storm Kalmaegi, projected to enter the East Sea early on November 5 and become the 13th storm of 2025.

Kalmaegi’s path and rainfall intensity may be influenced by various atmospheric conditions. Authorities and residents in at-risk areas are advised to stay informed and prepare accordingly.

Latest on storm Kalmaegi

Storm Kalmaegi continues moving swiftly and is expected to enter the East Sea with high intensity.

By 1 a.m. on November 7, the storm could reach coastal waters from Quang Ngai to Dak Lak with winds at level 13 and gusts up to level 16, accompanied by widespread heavy rain.

From the night of November 6, Kalmaegi could directly affect the region from Da Nang to Khanh Hoa, with winds onshore reaching level 10–12 and gusts up to level 15.

The East Sea may also see two to three more storms this November, especially as cold air strengthens across northern and north-central Vietnam. When combined with storm systems, this could lead to further heavy rainfall across central provinces.

Bao Anh