Hong Kong Typhoon and Rainstorm Signals Explained

Hong Kong sits in one of the most active tropical cyclone corridors in the western Pacific. Between May and October, storms roll through with enough regularity that the city has built an entire warning infrastructure around them. If you have just moved here (and especially if you arrived during our recommended first 24 hours checklist window), the system will seem confusing at first. Numbered typhoon signals, colour-coded rainstorm warnings, and a set of employer obligations that determine whether you go to work or stay home. This guide covers every signal you need to understand, what shuts down at each level, and what your rights are as an employee.

How the Warning System Works

The Hong Kong Observatory (HKO) operates two separate warning systems that can run simultaneously. The tropical cyclone warning signal system uses numbered signals (1, 3, 8, 9, 10) to indicate the threat level from an approaching typhoon. The rainstorm warning signal system uses colour codes (Amber, Red, Black) to indicate the severity of rainfall. During typhoon season, it is entirely possible to have both a typhoon signal and a rainstorm warning active at the same time, because typhoons bring heavy rain.

The key thing to understand is that typhoon signals are based on proximity and local wind conditions, not on the storm’s overall strength. A powerful super typhoon passing 500 kilometres south may only trigger a T3 in Hong Kong, while a weaker storm making a direct hit could warrant a T8 or higher. Download the MyObservatory app from the HKO. It sends push notifications the moment any signal is raised or lowered, and it is the single most reliable source of weather information in the city.

Signal No. 1: Standby

The T1 signal means a tropical cyclone has been identified within roughly 800 kilometres of Hong Kong and may approach the territory. At this stage, life continues completely normally. Shops, offices, schools, and transport all operate as usual.

What to do: keep an eye on the HKO forecasts. If you have outdoor plans for the next 48 hours, start thinking about a backup. Stock up on water, snacks, and make sure your phone is charged. For a broader look at what typhoon season means for daily life, our typhoon season guide covers the full picture.

Signal No. 3: Strong Wind

T3 means strong winds of 41 to 62 km/h are affecting Hong Kong, with gusts that can exceed 110 km/h in exposed areas. The storm is getting closer, and you will feel it.

At T3, kindergartens and some nurseries close. Most schools for older children remain open. Public transport continues to operate, though some ferry services (particularly to the outlying islands) may be suspended or run on reduced schedules. If you live somewhere like Cheung Chau or another outlying island, pay close attention to ferry cancellations at this stage.

Most offices and shops remain open during T3. Outdoor events and construction work may be suspended. Hiking trails become dangerous due to falling branches and landslip risk.

Signal No. 8: The One That Stops the City

This is the signal every expat needs to understand, because it is the one that determines whether you go to work. T8 indicates gale or storm force winds of 63 to 117 km/h, with gusts that can exceed 180 km/h. The HKO issues a Pre-No. 8 Special Announcement approximately two hours before raising the signal, giving employers and commuters time to prepare.

T8 comes in four directional variants (NW, SW, NE, SE) indicating where the strongest winds are coming from. For practical purposes, the direction does not change what closes. All four variants carry the same impact.

What shuts down at T8: schools close. Most shops and restaurants close. Government offices close. Buses gradually suspend service. Ferries stop. The MTR continues to run at reduced frequency during T8 (this is important, since it is your most reliable transport option if you need to get home). Taxis become extremely scarce, and surge pricing on ride-hailing apps can be severe. Cross-border transport to Shenzhen may be affected, with some checkpoints adjusting their operating hours.

The Airport Express continues running during T8 but suspends during T9 and above. If you are catching a flight during typhoon season, monitor signals closely and allow extra time.

Signals No. 9 and No. 10: When It Gets Serious

T9 is a transitional signal indicating that gale or storm force winds are increasing or expected to increase significantly. It is relatively rare and usually signals that T10 is imminent or that the eye of the storm is passing very close to Hong Kong.

T10 is the highest possible signal, indicating hurricane force winds exceeding 118 km/h with gusts above 220 km/h. The storm is either making a direct hit or passing extremely close. At T10, all public transport stops. The MTR suspends service. Stay indoors, away from windows and glass doors. Do not go outside under any circumstances.

T10 is rare. Hong Kong has only experienced it a handful of times in the past two decades. Super Typhoon Mangkhut in September 2018 and Super Typhoon Saola in September 2023 both brought T10 conditions and caused significant damage across the territory. When T10 is hoisted, expect shattered windows in high-rise buildings, uprooted trees blocking major roads, and widespread power outages that can last for days in the worst-hit areas. If you live above the 20th floor, move to an interior room with no exterior windows.

Rainstorm Amber: The First Alert

Switching to the rainstorm system. The Amber rainstorm warning is issued when heavy rain exceeding 30 millimetres per hour has fallen or is expected to fall across Hong Kong.

At Amber, life continues largely as normal. Schools remain open and exams proceed as scheduled. Transport operates normally. The signal is essentially telling you to be aware that conditions may worsen. If you are heading out, carry an umbrella and avoid low-lying areas that are prone to flooding, particularly underpasses, tunnels, and areas near rivers and drainage channels.

Rainstorm Red: Outdoor Work Stops

The Red rainstorm warning means rainfall has exceeded 50 millimetres per hour over a wide area. This is serious rain that causes road flooding and significant traffic disruption.

At Red, outdoor workers should cease work. Indoor workers continue as normal if transport is available and safe. For schools, the rule depends on timing: if the Red signal is issued before students have left home, they should stay home. If students are already at school, they remain there until conditions improve and it is safe to travel.

Flooding becomes a real risk at Red. Avoid any area near watercourses, hillsides (landslip risk), or known flooding blackspots. The HKO maintains a list of flood-prone areas on their website.

Rainstorm Black: Stay Indoors

The Black rainstorm warning is the most severe, issued when rainfall exceeds 70 millimetres per hour. At this level, conditions are dangerous and everyone should seek shelter immediately.

All outdoor work stops. Employers are advised not to require staff to travel to work. If you are already at your workplace, stay there until the warning is cancelled or downgraded. Government temporary shelters open during Black rainstorm conditions. If you need shelter, call the hotline at 2835 1473 for the nearest location.

Schools follow the same rule as Red: students already at school stay there, students at home remain home. The Education Bureau issues specific announcements via radio and the GovHK website.

One important difference from typhoon signals: rainstorm warnings can be issued and cancelled much more rapidly than typhoon signals. A Black rainstorm can appear with little warning and end within an hour, or it can persist for several hours. The unpredictability is part of what makes Hong Kong’s rainstorm season challenging.

Work Rules: What Your Employer Owes You

This is the section most expats actually need. The Labour Department’s Code of Practice sets out clear guidelines for work arrangements during adverse weather.

For typhoons, the key trigger is the Pre-No. 8 announcement. Once the HKO issues it, employers should begin releasing non-designated staff in stages so they can get home safely before the full T8 signal is raised. “Non-designated” means anyone who has not been specifically identified in advance as essential for operations during a typhoon.

Designated staff (those required to work during T8 or above) should be kept to the absolute minimum. Employers must provide these staff with an extra duty allowance and a special travelling allowance. If you are designated, your employer should have told you in advance and the arrangement should be documented.

After T8 is lowered back to T3 or below, employees are generally expected to return to work within two hours. However, the government introduced “Extreme Conditions” arrangements in 2023, which can extend the stay-home period even after the typhoon signal is lowered if conditions (such as fallen trees, flooding, or transport disruption) remain dangerous.

A critical legal point: under the Employees’ Compensation Ordinance, your employer is liable for compensation if you are injured while commuting to or from work within four hours before or after your working hours on a day when T8 or above is in force. This means your commute during a typhoon is treated as work-related for insurance purposes.

For rainstorms, the rules are simpler. Amber has no impact on work obligations. At Red, outdoor workers stop but indoor workers continue. At Black, employers should not require attendance unless prior arrangements have been established. In practice, most employers follow a “use common sense” approach during rainstorms, but the Code of Practice is there to protect you if a dispute arises.

What to Do During a Typhoon or Rainstorm

A practical checklist for weathering any storm in Hong Kong.

Before the storm: stock up on drinking water (at least 2 litres per person per day for 48 hours), non-perishable food, torches, and batteries. Fully charge all devices. If you live in a village house, consider taping large windows with masking tape in an X pattern and securing any outdoor furniture that could become a projectile.

During the storm: stay indoors and away from windows. Do not attempt to drive. If you lose power, report it to CLP (2678 2678) or HK Electric (2555 4999). If you need food delivered, delivery apps like Keeta and Foodpanda typically continue operating during T3 and sometimes early T8, but suspend during T8 proper and above.

After the storm: be cautious when going outside. Fallen trees, loose signage, and debris are common. Avoid coastal areas and hillsides for at least 24 hours after heavy rain (landslip risk persists). Check the HKO website for any ongoing warnings before resuming outdoor activities.

Quick Reference: All Signals at a Glance