What it does
Search any Hong Kong district or neighbourhood. The app finds the nearest sensor model, blends live feeds when available, and gives practical health advice instead of a wall of readings.
Breathe.
Hong Kong air quality, translated into a readable map, practical health advice, and nearby escape options.
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About Breathometer HK
Air quality, translated.
Most air-quality sites show numbers first. Breathometer HK starts with the question people actually have: can I go outside, exercise, open windows, or should I avoid roadside exposure?
Where data comes from
Official HK EPD AQHI station readings provide the base. AQICN / WAQI geo-feed readings are used for PM2.5 and NO₂ when a token is configured, then averaged with the EPD model.
Why the map looks different
The background is a topographic-style air map: contour lines show terrain, station dots show monitoring points, and colored blooms show the estimated air-quality impact around your searched area.
When no exact sensor exists
The app uses a 3-nearest-neighbour model with inverse-distance weighting, then labels the model so you know whether the result is exact, nearest, or blended.