EPD - 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).

Annual AQI Values

Air Pollutant Concentrations

Air Pollutant Concentrations (μg/m³)
Period: July 2019 - June 2020

General stations

Central/Western	Southern	Eastern	Kwun Tong
Sham Shui Po	Kwai Chung	Tsuen Wan	Tseung Kwan O
Yuen Long	Tuen Mun	Tung Chung	Tai Po
Sha Tin	North	Tap Mun

Roadside stations

Causeway Bay

Central

Mong Kok

Air Pollutant Concentrations (μg/m³)
Period: July 2019 - June 2020

General Stations

Station	NO₂	PM₁₀	PM_2.5
Central/Western	34	28	18
Southern	NA	NA	NA
Eastern	35	30	17
Kwun Tong	43	36	19
Sham Shui Po	47	31	17
Kwai Chung	51	27	17
Tsuen Wan	40	27	18
Tseung Kwan O	27	28	15
Yuen Long	39	36	19
Tuen Mun	44	38	23
Tung Chung	30	27	17
Tai Po	33	28	18
Sha Tin	30	26	16
North	NA	NA	NA
Tap Mun	8	29	16

Pollutant concentrations in micrograms per cubic metre (μg/m³)

Roadside Stations

Station	NO₂	PM₁₀	PM_2.5
Causeway Bay	76	40	25
Central	76	34	21
Mong Kok	79	33	21

Pollutant concentrations in micrograms per cubic metre (μg/m³)

Annual AQI Values
Period: July 2019 - June 2020

General stations

Central/Western	Southern	Eastern	Kwun Tong
Sham Shui Po	Kwai Chung	Tsuen Wan	Tseung Kwan O
Yuen Long	Tuen Mun	Tung Chung	Tai Po
Sha Tin	North	Tap Mun

Roadside stations

Causeway Bay

Central

Mong Kok

Annual AQI Values
Period: July 2019 - June 2020

General Station

Station	NO₂	PM₁₀	PM_2.5
Central/Western	0.85	1.40	1.80
Southern	NA	NA	NA
Eastern	0.88	1.50	1.70
Kwun Tong	1.08	1.80	1.90
Sham Shui Po	1.18	1.55	1.70
Kwai Chung	1.28	1.35	1.70
Tsuen Wan	1.00	1.35	1.80
Tseung Kwan O	0.68	1.40	1.50
Yuen Long	0.98	1.80	1.90
Tuen Mun	1.10	1.90	2.30
Tung Chung	0.75	1.35	1.70
Tai Po	0.83	1.40	1.80
Sha Tin	0.75	1.30	1.60
North	NA	NA	NA
Tap Mun	0.20	1.45	1.60

AAQI = 12-month rolling concentrations/Annual WHO AQG concentration

Roadside

Station	NO₂	PM₁₀	PM_2.5
Causeway Bay	1.90	2.00	2.50
Central	1.90	1.70	2.10
Mong Kok	1.98	1.65	2.10

AAQI = 12-month rolling concentrations/Annual WHO AQG concentration

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):