Typhoon signals and black rain: what T8 and the warnings actually mean
Hong Kong gets serious weather and has a warning system to match. The signals are numbered, the rain warnings are colour-coded, and the difference between signal 3 and signal 8 is the difference between a windy afternoon and a city that stops. Here is what each one actually changes.
1The typhoon signal ladder
| Signal | Meaning | What changes |
|---|---|---|
| 1 | A tropical cyclone is within about 800 km | Nothing. It is a notice, not a warning to act. |
| 3 | Strong wind expected, sustained 41–62 km/h | Ferries may reduce service; outdoor attractions close early; otherwise normal. |
| 8 | Gale or storm force wind, sustained 63–117 km/h | Schools and most offices close, ferries suspend, buses run reduced routes, the city largely shuts. |
| 9 | Wind increasing, 118–220 km/h | Almost everything stops. Airport Express suspends because its route is exposed. |
| 10 | Hurricane force, above 220 km/h | Stay inside, away from windows. Nothing runs. |
Signal 8 is the hinge. Below it, the city functions with disruption; at 8 and above, the assumption is that you are indoors.
2What actually closes at signal 8
- Schools and government offices close, and most private employers follow.
- Ferries suspend — including the Star Ferry and outlying island routes.
- Buses move to reduced service and many routes stop entirely.
- The MTR keeps running in tunnels but reduces frequency and closes exposed sections.
- Shops and restaurants vary: chains often stay open until the signal is hoisted, then close.
The signal is hoisted with advance notice — usually a couple of hours — which is why supermarkets fill up beforehand. That window is when you should buy water and food, not after.
3Rainstorm warnings: amber, red, black
Separate from typhoons, heavy rain triggers its own three-level warning:
- Amber — very heavy rain, 30 mm in an hour. Expect flooding in low-lying areas.
- Red — 50 mm in an hour. Schools close, traffic slows badly.
- Black — 70 mm or more in an hour, widespread. This is the one to take seriously: stay indoors, avoid underpasses and steep roads.
Black rainstorm warnings can arrive with very little lead time, and the flooding they cause is the real danger — not the wind. Do not walk or drive through moving water on a road.
4The "extreme conditions" announcement
After a severe typhoon or a black rainstorm, the government may issue an extreme conditions announcement. It extends the shutdown beyond the moment the signal is lowered, because roads, transport and services have not recovered.
In practice: if you hear that extreme conditions are in force, do not assume the city is back to normal just because the signal dropped. Wait for transport to resume properly; the queues when it does are substantial.
5If you are visiting when one hits
- Stay in. A typhoon is not a spectacle. Waterfronts and promenades are the worst places to be, and police close them.
- Stock up early, as soon as signal 3 or a red rain warning is mentioned.
- Check your flight. Cancellations are common at signal 8; contact the airline rather than going to the airport to wait.
- Keep your hotel informed and ask what their arrangement is for meals if restaurants shut.
- Watch the Observatory rather than social media. Our weather page shows current readings and active warnings from the Hong Kong Observatory.
The city recovers fast — usually within a day — and the day after a typhoon is often unusually clear.
Quick answers
Does everything close at typhoon signal 8?
Most of it: schools, government offices, ferries, many buses and shops. The MTR continues in tunnels with reduced service, and some restaurants stay open until the signal goes up.
Will my flight be cancelled at signal 8?
Frequently, yes. Airlines cancel proactively at signal 8 and above. Contact the airline rather than travelling to the airport to wait.
What is a black rainstorm warning?
Rain of 70 mm or more in an hour across a wide area. It means flash flooding risk — stay indoors and avoid underpasses and steep roads.
How long does a typhoon last in Hong Kong?
Usually a day or less of direct impact. Signal 8 typically lasts several hours to a day, after which transport resumes gradually and queues build.
Where should I check warnings?
The Hong Kong Observatory is the official source. Our weather page shows its current readings and active warnings, updated through the day.
Sources: Hong Kong Observatory — warnings · Hong Kong Observatory — rainstorm warnings. Last checked 28 October 2026; operators and government departments can change fares and arrangements at any time.