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Classification of Tropical Cyclones

Tropical cyclones are classified in accordance with the World Meteorological Organization's recommendation by the maximum sustained wind speeds near the centre. In Hong Kong, the classification is defined in terms of wind speeds averaged over a period of 10 minutes as follows :
Tropical Cyclone Classification   Maximum 10-minute mean wind near the centre
Tropical Depression   41 to 62 km/h
Tropical Storm   63 to 87 km/h
Severe Tropical Storm   88 to 117 km/h
Typhoon   118 to 149 km/h
Severe Typhoon*   150 to 184 km/h
Super Typhoon*   185 km/h or above

*New categories starting 2009