Latest Annual AQI
The Annual Air Quality Index (AAQI) is the ratio of the past 12-month rolling average concentration to the annual air quality guidelines (AQG) of the World Health Organization (WHO).
Air Pollutant Concentrations (μg/m3)
Period: November 2020 - October 2021
General Stations
| Station | NO2 | PM10 | PM2.5 |
|---|---|---|---|
| Central/Western | 33 | 26 | 16 |
| Southern | 30 | 26 | 13 |
| Eastern | 35 | 30 | 15 |
| Kwun Tong | 47 | 33 | 17 |
| Sham Shui Po | 47 | 29 | 14 |
| Kwai Chung | 51 | 26 | 16 |
| Tsuen Wan | 43 | 25 | 16 |
| Tseung Kwan O | 25 | 24 | 13 |
| Yuen Long | 37 | 31 | 16 |
| Tuen Mun | 43 | 37 | 20 |
| Tung Chung | 26 | 26 | 16 |
| Tai Po | 32 | 27 | 16 |
| Sha Tin | 30 | 26 | 14 |
| North | 35 | 26 | 15 |
| Tap Mun | 10 | 25 | 14 |
Roadside Stations
| Station | NO2 | PM10 | PM2.5 |
|---|---|---|---|
| Causeway Bay | 71 | 40 | 24 |
| Central | 68 | 31 | 19 |
| Mong Kok | 69 | 31 | 19 |
Annual AQI Values
Period: November 2020 - October 2021
General Station
| Station | NO2 | PM10 | PM2.5 |
|---|---|---|---|
| Central/Western | 0.83 | 1.30 | 1.60 |
| Southern | 0.75 | 1.30 | 1.30 |
| Eastern | 0.88 | 1.50 | 1.50 |
| Kwun Tong | 1.18 | 1.65 | 1.70 |
| Sham Shui Po | 1.18 | 1.45 | 1.40 |
| Kwai Chung | 1.28 | 1.30 | 1.60 |
| Tsuen Wan | 1.08 | 1.25 | 1.60 |
| Tseung Kwan O | 0.63 | 1.20 | 1.30 |
| Yuen Long | 0.93 | 1.55 | 1.60 |
| Tuen Mun | 1.08 | 1.85 | 2.00 |
| Tung Chung | 0.65 | 1.30 | 1.60 |
| Tai Po | 0.80 | 1.35 | 1.60 |
| Sha Tin | 0.75 | 1.30 | 1.40 |
| North | 0.88 | 1.30 | 1.50 |
| Tap Mun | 0.25 | 1.25 | 1.40 |
Roadside
| Station | NO2 | PM10 | PM2.5 |
|---|---|---|---|
| Causeway Bay | 1.78 | 2.00 | 2.40 |
| Central | 1.70 | 1.55 | 1.90 |
| Mong Kok | 1.73 | 1.55 | 1.90 |
Remarks:
(1) The AAQI is updated monthly. The AAQI is calculated based on validated monitoring data.
(2) An AAQI greater than one indicates that the health risk resulted from long-term exposure is higher than that of the WHO's annual AQG, whereas an index below one means a lower risk.
(3) WHO’s annual AQG (2006):
Reference: http://www.who.int/phe/health_topics/outdoorair/outdoorair_aqg/en/index.html
Annual WHO AQG
(μg/m3)
NO2
40
PM10
20
PM2.5
10
For further information about the annual AQI, please visit the FAQ.
(4) NO2 - nitrogen dioxide, PM10 - respirable suspended particulates, PM2.5 - fine suspended particulates