Vietnam is a southeast Asian country, and is the easternmost country of mainland Southeast Asia. Because it is located in the easternmost part and borders the South China Sea, it is often affected by tropical cyclones. Tropical cyclones in this area are considered to be part of the Northwest Pacific basin. There are about 11 to 13 tropical cyclones entering the South China Sea during the period from June to November every year.
Every year, there are about 4 to 6 tropical cyclones that make landfall or directly affect the mainland. According to the climate law, the tropical cyclones season in Vietnam gradually slows down from North to South, with the highest storm frequency in the coastal provinces from Quảng Ninh to Thanh Hoá and the lowest in the area from Lâm Đồng to Cà Mau and An Giang. Tropical cyclone have a strong impact and cause damage to both the economy and life of this country.
Any tropical cyclone entering the South China Sea west of 120°E and north of 5°N are monitored and reported by the National Center for Hydro-Meteorological Forecasting (NCHMF) together with the Japan Meteorological Agency (JMA) and the Joint Typhoon Warning Center (JTWC). NCHMF also regularly issues weather bulletins and advisories to the public, especially during storms. The Vietnamese government also pays attention to storm and tropical depression prevention and control, and natural disasters in general. The country has established the National Civil Defense Steering Committee (formerly the National Steering Committee for Natural Disaster Prevention and Control; National Committee for Incident, Disaster Response and Search and Rescue) to develop and implement plans to respond to storms, tropical depressions and other types of natural disasters. A five-level disaster risk warning scale, issued under Decision No. 18/QD-TTg in 2021 of the Prime Minister of Vietnam, will apply to all or part of the provinces and localities affected by tropical cyclones when they are forecast to have the potential to affect mainland Vietnam.
General overview
Etymology and Definition Bão comes from the word "暴". (Hán-Việt: bạo). According to Hoang Phê (2003), "Bão" means "a large-scale whirlwind in an area with very low air pressure, often originating from the open sea, with violent destruction due to strong winds and heavy rain"
Nguyễn Đức Ngữ (1998) defines cyclones as atmospheric disturbances with pressure decreasing from the edges to the center, and in the Northern Hemisphere the wind blows counterclockwise.
The National Center for Hydro-Meteorological Forecasting (NCHMF) defines storms and tropical depressions, collectively known as tropical cyclones, as "a whirlwind, up to hundreds of kilometers in diameter, forming over tropical seas; in the Northern Hemisphere, winds blow into the center in a counterclockwise direction; the atmospheric pressure in the storm is much lower than the surrounding area and is usually lower than 1000mbar". Depending on location and intensity, tropical cyclones are known by different names. In the Northwest Pacific basin, including Vietnam, meteorologists use the term typhoon (in English) to refer to tropical storms with minimum wind speeds of , according to the regulations of the Japan Meteorological Agency (JMA), the unit established the Regional Specialized Meteorological Center (RSMC Tokyo) of the Northwest Pacific as assigned by the World Meteorological Organization (WMO).
Meteorology +Vietnam's Tropical Cyclone Intensity Scale Category Sustained winds Beaufort number Tropical Depression ≤33 knots≤61 km/h6-7 Tropical Storm 34–47 knots62–88 km/h8-9 Severe Tropical Storm 48–63 knots89–117 km/h10-11 Typhoon 64–99 knots118–183 km/h12-15 Super Typhoon ≥100 knots≥184 km/h ≥16 In Vietnam, as in the Northwest Pacific basin, tropical cyclone are generally active year-round from January to December. However, the tropical cyclone season in Vietnam is usually considered to be from June to November. On average, the South China Sea records 11 to 13 tropical cyclone in many years and the tropical cyclone season in the South China Sea is assessed to slow down from North to South. The strongest activity is in July, August, September, and October with an average of about 2 tropical cyclones per month. However, there are some years when the South China Sea has many storms. In 2017, a record 20 tropical cyclones (including 16 typhoons/storms and 4 tropical depressions) were recorded. Conversely, there are also years with few storms, in which the year with the fewest storms in the South China Sea was 1969 with a total of 5 tropical cyclones. A study was investigated in the correlation of rainfall and tropical cyclones during El Niño and La Niña seasons, and showed that there is an increase of rainfall and tropical cyclones during La Niña seasons.
Vietnam currently uses the Beaufort wind scale to measure storm intensity. Before 2006, the wind scale in Vietnam only used up to level 12 and above. After typhoon Chanchu and Xangsane in 2006, the Vietnamese Government issued Decision 245/2006/QD-TTg, stipulating the expansion of the wind scale in Vietnam to level 17 (maximum 220 km/h). Currently in Vietnam, according to Decision 18/2021/QD-TTg on forecasting, warning, transmitting information on natural disasters and disaster risk levels issued by the Prime Minister, the tropical cyclone scale in Vietnam includes 5 types: tropical depression, tropical storm, severe tropical storm, typhoon and super typhoon. The wind scale in Vietnam according to this regulation also stops at level 17.
Storm zoning + Storm zoning table in Vietnam Region Area I Northeast (5 provinces) II Northwest (3 provinces) III Northern Delta, Midlands and Thanh Hoá (8 provinces) IV Nghệ An to Huế (4 provinces) V Đà Nẵng to Gia Lai (3 provinces) VI Đắk Lắk to Khánh Hoà (2 provinces) VII West of Quang Ngai, Gia Lai,Dak Lak and Lam Dong provinces VIII Lâm Đồng to Cà Mau—An Giang and Southern (9 provinces) After Super Typhoon Haiyan in 2013, the Vietnamese Government began developing scenarios to respond to typhoons and super typhoons. Decision No. 1857/QD-BTNMT dated August 29, 2014 of the Ministry of Natural Resources and Environment divided the storm zone in Vietnam into 5 regions: from Quảng Ninh to Thanh Hoá, Nghệ An to Thừa Thiên-Huế, Đà Nẵng to Bình Định, Phú Yên to Khánh Hoà and Ninh Thuận to Cà Mau. By 2016, the Ministry of Natural Resources and Environment continued to divide Vietnam into 8 regions. These 8 regions include: the Northeast region; the Northwest region; the Northern plains, midlands and coastal areas from Quang Ninh to Thanh Hoa; from Nghệ An to Huế; from Đà Nẵng to Bình Định (from July 1, 2025, Gia Lai province); from Phú Yên to Ninh Thuận (from July 1, 2025, Dak Lak province and Khánh Hoà province); the Central Highlands and the South (including Bình Thuận province, from July 1, 2025, Lâm Đồng province)
However, according to the decentralization of hydrometeorological management in Vietnam from 2025, 3 hydrometeorological stations are arranged in 3 regions: Northern Hydrometeorological Station; Central Hydrometeorological Station; Southern Hydrometeorological Station. Previously, according to Decision 03/2018/QD-TTg, the Northern region of Vietnam was divided into 4 hydrometeorological stations including Northwest, Northeast, Viet Bac and Northern Delta. By 2023, Vietnam will have 7 meteorological stations including the Northern Mountains, Northern Midlands and Delta, North Central, Central Central, South Central, Central Highlands and South. In weather forecasting and warning, Vietnam is divided into 6 regions including Northwest, Northeast, Thanh Hoa to Hue, Da Nang to Lam Dong, Central Highlands and South. In addition, there are many different studies for different ways of distributing storm landing zones in Vietnam.
Landfall
Frequency, trajectory and intensity On average, Vietnam is affected by 6–8 tropical cyclones annually. including between 4-6 tropical cyclones that made landfall in the country. According to research by Nguyễn Văn Thắng and colleagues, September was the month with the highest number of tropical cyclone making landfall in Vietnam during the period 1961–2014. However, there have been years when no tropical cyclone made landfall in Vietnam, such as 1976, 2002, and 2023. The longest period without a tropical cyclone making landfall on the Vietnamese coast was from October 16, 2022, to July 22, 2024 (646 days). According to one study, the year with the most tropical cyclone hitting Vietnam was 1973, with 12 tropical cyclones. Meanwhile, another study estimated that in 1978 there were as many as 13 tropical cyclones affecting mainland Vietnam. Some studies also indicate that in years when La Niña occurs, the average number of tropical cyclone affecting Vietnam reaches 8.3 per year, significantly more than in years with El Niño, which average 5.3 per year. Furthermore, under La Niña conditions, the frequency of tropical cyclone affecting Central Vietnam also increases. For example, the successive tropical cyclones that hit central Vietnam in 2020 caused catastrophic floods in this region. According to documents from Vietnam's Ministry of Natural Resources and Environment, the highest average frequency of tropical cyclone landfall is in the northern delta and midland regions and the coastal areas from Quảng Ninh to Thanh Hoá, with 2.0 to 2.5 tropical cyclones per year. According to Nguyễn Xuân Chính and Nguyễn Đại Minh, the northern coastal region has the highest density of tropical cyclone (calculated per 100 km of coastline) in the country, accounting for 43% of all strong typhoons. In addition, storms that hit northern Vietnam are also considered to generate stronger winds than storms that hit southern provinces.
Furthermore, documents from the Vietnamese Ministry of Natural Resources and Environment also indicate that the coastal area of Northern Vietnam once recorded the highest wind speed in Vietnam at level 15 with gusts up to level 17, corresponding to the wind speed recorded during Typhoon Wendy in 1968, which was with gusts of at the Phù Liễn meteorological station, exceeding the capabilities of the measuring instrument. When Typhoon Sarah made landfall in Hải Phòng on July 21, 1977, the strongest wind gusts recorded at Phù Liễn were In 1998, Nguyễn Đức Nghĩa stated that the lowest atmospheric pressure recorded for a typhoon making landfall in Vietnam belonged to Typhoon Cecil in 1985, with measured at Đông Hà, Quảng Trị. In 2024, a report from the Vietnamese meteorological agency stated that Super Typhoon Yagi recorded sustained wind speeds of gusts (equivalent to level 15 with gusts exceeding level 17) at Bãi Cháy, Quảng Ninh,. Website although some domestic public reports indicate sustained wind speeds at Bãi Cháy are gusts . Website Furthermore, the atmospheric pressure at this station during Super Typhoon Yagi was recorded at , which is also the lowest atmospheric pressure recorded for a typhoon making landfall in Vietnam since complete data became available. The Vietnamese government also assessed Super Typhoon Yagi as the strongest super typhoon in the South China Sea in the past 30 years and the strongest typhoon to hit Vietnam in the past 70 years. Storm wind speeds exceeding have been repeatedly recorded in the Red River Delta and coastal areas of Quảng Ninh.
1800s October 5, 1881 - A typhoon struck what is now northern Vietnam, producing a storm surge that flooded the city of Hai Phong, killing around 3,000 people.
1980s September 1980 - Tropical Storm Ruth struck Thanh Hóa province, causing torrential flooding which killed 164 people. 97 people suffered injuries.
1990s November 2, 1997 - Tropical Storm Linda struck southern Vietnam, where it wrecked thousands of fishing boats and killed at least 3,111 people.
2000s