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: February 2022 - January 2023

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: February 2022 - January 2023

General Stations

Station	NO₂	PM₁₀	PM_2.5
Central/Western	29	22	14
Southern	25	25	12
Eastern	32	23	13
Kwun Tong	44	24	14
Sham Shui Po	42	24	12
Kwai Chung	43	23	15
Tsuen Wan	39	23	14
Tseung Kwan O	21	23	14
Yuen Long	36	25	16
Tuen Mun	38	32	18
Tung Chung	24	22	13
Tai Po	27	21	14
Sha Tin	26	21	13
North	30	23	14
Tap Mun	7	20	12

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

Roadside Stations

Station	NO₂	PM₁₀	PM_2.5
Causeway Bay	65	34	20
Central	62	26	17
Mong Kok	63	26	16

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

Annual AQI Values
Period: February 2022 - January 2023

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: February 2022 - January 2023

General Station

Station	NO₂	PM₁₀	PM_2.5
Central/Western	0.73	1.10	1.40
Southern	0.63	1.25	1.20
Eastern	0.80	1.15	1.30
Kwun Tong	1.10	1.20	1.40
Sham Shui Po	1.05	1.20	1.20
Kwai Chung	1.08	1.15	1.50
Tsuen Wan	0.98	1.15	1.40
Tseung Kwan O	0.53	1.15	1.40
Yuen Long	0.90	1.25	1.60
Tuen Mun	0.95	1.60	1.80
Tung Chung	0.60	1.10	1.30
Tai Po	0.68	1.05	1.40
Sha Tin	0.65	1.05	1.30
North	0.75	1.15	1.40
Tap Mun	0.18	1.00	1.20

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

Roadside

Station	NO₂	PM₁₀	PM_2.5
Causeway Bay	1.63	1.70	2.00
Central	1.55	1.30	1.70
Mong Kok	1.58	1.30	1.60

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):