香港天氣通 — Hong Kong weather, typhoon signals and rain warnings
In Hong Kong the temperature is rarely the question. Whether the T8 is going up, and whether the amber has turned black, is — so those come first.
A weather app for a city with weather policy
Most weather apps are built around a temperature and an icon, with warnings as an afterthought somewhere below the fold. Hong Kong does not work that way. A typhoon signal or a rainstorm warning determines whether offices open, whether schools run and whether it is sensible to leave the building — and the difference between an amber and a black rainstorm warning is the difference between an umbrella and staying put.
香港天氣通 puts the warnings at the top, pulls everything from the Hong Kong Observatory's open data, and can notify you when a signal changes rather than waiting for you to check.
What the Hong Kong weather app shows
Warnings first, then the forecast, then the detail.
- Active warnings, prominently. Typhoon signals and rainstorm warnings appear as a banner and a strip on the home screen, not buried in a secondary tab. When nothing is active, that space is quiet.
- A typhoon track. When a storm is approaching, the track is drawn rather than described. Seeing the projected path relative to Hong Kong answers the question that a signal number alone does not.
- Nine-day and hourly forecasts. The Observatory's nine-day outlook plus an hourly row, with a temperature range bar rather than a single number — useful in a city where an eight-degree daily swing in winter is normal.
- Conditions from the station near you. Hong Kong's microclimates are real; the temperature in Tai Po and on Hong Kong Island can differ meaningfully. Readings are shown per weather station.
- Air quality. The Air Quality Health Index from the Environmental Protection Department, on its published scale — 1 to 3 low, 4 to 6 moderate, 7 high, 8 to 10 very high, above 10 serious — with the health bands explained.
- Warning notifications. Local notifications when warnings change, so you find out the T8 is going up without opening anything.
- Commuter cards and a sky that matches. Short practical summaries for going out, and a background that reflects the actual sky and time of day — pleasant rather than essential, but it makes the app one you open.
Straight from the Observatory
All data comes from the Hong Kong Observatory's public open data endpoints and the EPD's air quality feed. There is no third-party forecast model in between reinterpreting it, which matters in Hong Kong because the Observatory's warning is the one the city actually acts on — an international app's own storm assessment is interesting and operationally irrelevant.
Requests are cached to avoid hammering the endpoints, with retries on transient failures. Location is used only to pick the nearest station, and there is no account.
Who it is for
Anyone in Hong Kong deciding whether to travel, especially in summer. Parents checking whether school is on. People who work outdoors or commute a long way, where a black rainstorm warning changes the whole day.
It also suits residents who want the Observatory's own numbers in a readable form rather than through an international weather brand, and people with respiratory conditions for whom the AQHI is the reading that matters more than the temperature.
Data sources
Weather observations, forecasts and warnings come from the Hong Kong Observatory's open data API. Air Quality Health Index data comes from the Environmental Protection Department. The app is unofficial and is not operated by or affiliated with either body.
During a severe event, the Observatory's own announcements are authoritative. The app is free and ad-supported, with no account required.
Frequently asked questions
Will it notify me when the typhoon signal changes? Yes. Local notifications can be enabled for warning changes, including typhoon signals and rainstorm warnings.
Where does the data come from? The Hong Kong Observatory's open data API for weather, forecasts and warnings, and the Environmental Protection Department for the Air Quality Health Index.
Does it show the typhoon track? Yes. When a storm is active, the projected track is drawn relative to Hong Kong rather than only described.
Does it account for different districts? Yes. Readings are shown per weather station — conditions vary meaningfully across the territory.
Is it an official Observatory app? No. It is unofficial and built on public open data.