Tropical cyclones, also known as typhoons and hurricanes depending on where you live, normally occur between May and November in Hong Kong.
Whenever the center of a tropical cyclone is within 800 km of Hong Kong and poses a threat to the territory, the Observatory will issue a warning. The bulletins include the latest position and expected movement of the storm, and its wind strength, rainfall and sea level in Hong Kong.
Check the Hong Kong Observatory (HKO) weather app or listen to radio or television broadcasts and follow the advice and recommended precautions. Be prepared to deal with quickly changing conditions. High winds may persist even after the storm has moved away from Hong Kong, so stay indoors until the winds moderate.
Be prepared to deal with quickly changing conditions. High winds may persist even after the storm has moved away from Hong Kong, so stay indoors until the winds moderate.
Signals for cyclone warnings use a numbering system, as follows:
Signal Typhoon 1 (T1)
This is a standby signal indicating that a tropical cyclone is centered within 800 km of Hong Kong and may later affect the territory.
Action: If you are planning an outing, remember that the cyclone may affect your plans later. Check the Hong Kong Observatory (HKO) weather app or listen to radio or television broadcasts to follow the progress of the storm.
Signal Typhoon 3 (T3)
Strong winds are expected with a sustained speed of 41-62 km per hour. Gusts may exceed 110 km per hour. Winds are normally expected to become generally stronger in the harbor areas about 12 hours after this signal is issued. Kindergartens are closed when the T3 signal is issued.
Action: Secure all loose objects, particularly those on balconies and rooftops. Flower pots and other objects likely to be blown away should be taken indoors. Secure scaffolding and temporary structures. Clear drains to avoid blockage and overflows. Listen to radio, TV and HKO announcements for further information.
Signal Typhoon 8 (T8)
Gale- or storm-force winds are expected or blowing in the harbor with a sustained wind speed of 63-117 km per hour from the quarter indicated. Gusts may exceed 180 km per hour.
Action: Complete precautions immediately before gales commence. Lock all windows and doors. Insert reinforced shutters and gates if available. Apply adhesive or masking tape to large window panes in exposed positions to reduce damage that may be caused by broken glass.
Do not stand near windows on the exposed side of your house. Move all furniture and valuables away from these areas. Make sure you have a safe place to shelter in case windows are broken. Decide which rooms to use for shelter if windows on the exposed side are blown in or sucked out.
Owners of neon signs should arrange for the electricity supply to their signs to be shut off. Park your car where it is least likely to be damaged.
Signal Typhoon 9 (T9)
Gale- or storm-force winds are increasing or expected to increase significantly in strength.
Action: Stay indoors. Stay away from exposed windows and doors. Close all interior doors and make sure children are confined to the least exposed part of your home. Do not touch electrical cables that have blown loose. Only when the danger of fixing broken windows is removed should you do so. If you are away from home, find a safe place and stay there until the danger is over.
Signal Typhoon 10 + (T10)
Hurricane-force winds are expected or blowing.
Sustained wind speeds are reaching upwards from 118 km per hour. Gusts may exceed 220 km per hour.
Action: The same precautions apply as for a T8 or T9. While most housing is quite safe, nevertheless, windows can be blown in and should be taped. Air conditioners have been known to blow into rooms or be sucked out of windows.
Windows may leak. Do not allow children near windows, and remove beds from under windows. Close curtains to help prevent broken glass from flying into a room.
Do not be tempted to take risks and go outdoors while signals are up. Flying shop signs, loose scaffolding, or tree branches can be lethal, as can downed power lines in water. Remember that if the eye of the hurricane passes directly over Hong Kong there may be a temporary lull lasting a few minutes to several hours. Do not relax your guard, as the violent winds will resume from a different direction. Remain where you are and be prepared for destructive winds.
Many areas in Hong Kong are vulnerable to landslides and flooding, so when rainfall in Hong Kong is very heavy, the Observatory will issue warnings. There are three levels: Amber, Red and Black.
Issued when heavy rain exceeding 30 millimeters per hour has fallen or is expected to fall.
There is likely to be flooding in low-lying and poorly drained areas. Pay attention to weather changes. Kindergartens are closed when this signal is issued.
Issued when rainfall exceeding 50 mm per hour has fallen or is expected to fall, and is likely to continue.
Heavy rain could cause serious road flooding. Those who have to travel should consider road conditions carefully.
Indicates that rainfall exceeding 70 mm per hour has fallen or is expected to fall, and is likely to continue. It means that there is serious road flooding.
People should take shelter in a safe place. Most workers are not expected to go to work until the Black Rainstorm Warning is lowered. If you’re already at work or at school, you should stay where you are until the signal is lowered.
Special Actions for Severe Weather
For all intents and purposes, Hong Kong shuts down in case of a black rainstorm signal or T8 or above: offices and stores will generally be closed (or close early), taxis are sparse since most drivers don’t have insurance for typhoons, and other public transportation may be affected.
In the event a RED / BLACK rainstorm signal or T8 or above is in effect in the morning before school starts, school is cancelled and students should stay home. If any of these signals are raised after students are already at school, they should remain there until the end of school hours and conditions are safe for them to return home.
If the RED / BLACK signal or T8 or above is issued after students have set out for school, students should proceed normally to school unless road or traffic conditions ahead are not safe. School bus drivers should listen to radio broadcasts on the latest development of the rainstorm and ensure that students are taken to a safe place, normally the school, unless road or traffic conditions ahead warrant otherwise.
Schools should arrange to be open and appropriately staffed to look after any students arriving until it is safe for them to return home.