When is it called a super typhoon in Vietnam?

Based on the maximum wind speed of each storm, Vietnam classifies storms into: strong storms, very strong storms, and the highest category, super typhoons.

According to Clause 7 of Article 5 of Decision 18/2021/QD-TTg, a storm is defined as a tropical cyclone with maximum wind speeds of level 8 or higher and may have gusts.

Impact area of Super Typhoon Yagi.

According to wind speed, storms are classified as follows:

Storms with maximum wind speeds from level 10 to level 11 are referred to as strong storms;
Storms with maximum wind speeds from level 12 to level 15 are called very strong storms;
Storms with maximum wind speeds of level 16 or higher are classified as super typhoons.

Specific details regarding the wind speeds of each storm level are outlined in Appendix III attached to Decision 18/2021/QD-TTg as follows:

Thus, a storm is classified as a super typhoon when its maximum wind speed is level 16 or higher.

Disaster risk levels of super typhoons in Vietnam

Specifically, Article 42 of Decision 18/2021/QD-TTg stipulates the disaster risk levels due to tropical depressions and storms as follows:

Disaster risk level 3 includes the following cases:

Forecast tropical depression, storms at level 8 or level 9 operating in the South China Sea (including the Spratly and Paracel Islands); coastal waters; land areas of the Northwest, Northeast, Northern Delta, North Central, Central Coast, Central Highlands, Southern region;
Forecast strong storms at level 10 or level 11 operating in the South China Sea (including the Spratly and Paracel Islands); coastal waters, land areas of the Northwest, Northeast, Northern Delta, North Central, Central Coast, Central Highlands;
Forecast very strong storms at level 12 or level 13 operating in the South China Sea (including the Spratly and Paracel Islands).

Disaster risk level 4 includes the following cases:

Forecast strong storms at level 10 or level 11 operating on land in the Southern region;
Forecast very strong storms at level 12 or level 13 operating in coastal waters, land areas of the Northwest, Northeast, Northern Delta, North Central, Central Coast, Central Highlands;
Forecast very strong storms at level 14 or level 15 operating in coastal waters; land areas of the Northeast, Northern Delta, North Central, Central Coast;
Forecast storms at level 14 or higher operating in the South China Sea (including the Spratly and Paracel Islands).

Disaster risk level 5 includes the following cases:

Forecast very strong storms at level 12 or level 13 operating on land in the Southern region;
Forecast very strong storms at level 14 or level 15 operating on land in the Northwest, Northeast, Central Highlands, and Southern region;
Forecast super typhoons at level 16 or higher operating in coastal waters; land areas of the Northwest, Northeast, Northern Delta, North Central, Central Coast, Central Highlands, Southern region.

If a super typhoon operates in the South China Sea (including the Spratly and Paracel Islands), then the disaster risk level of the super typhoon is level 4; if the super typhoon operates in coastal waters or on land in the Northwest, Northeast, Northern Delta, North Central, Central Coast, Central Highlands, or Southern region, then the disaster risk level of the super typhoon is level 5.