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: January 2020 - December 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: January 2020 - December 2020

General Stations

Station	NO₂	PM₁₀	PM_2.5
Central/Western	32	25	16
Southern	NA	NA	NA
Eastern	34	27	14
Kwun Tong	43	32	16
Sham Shui Po	45	28	14
Kwai Chung	48	23	14
Tsuen Wan	36	24	15
Tseung Kwan O	23	24	12
Yuen Long	32	30	16
Tuen Mun	40	34	20
Tung Chung	28	25	14
Tai Po	30	24	15
Sha Tin	28	25	15
North	NA	NA	NA
Tap Mun	9	25	14

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

Roadside Stations

Station	NO₂	PM₁₀	PM_2.5
Causeway Bay	68	36	22
Central	68	29	17
Mong Kok	74	29	18

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

Annual AQI Values
Period: January 2020 - December 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: January 2020 - December 2020

General Station

Station	NO₂	PM₁₀	PM_2.5
Central/Western	0.80	1.25	1.60
Southern	NA	NA	NA
Eastern	0.85	1.35	1.40
Kwun Tong	1.08	1.60	1.60
Sham Shui Po	1.13	1.40	1.40
Kwai Chung	1.20	1.15	1.40
Tsuen Wan	0.90	1.20	1.50
Tseung Kwan O	0.58	1.20	1.20
Yuen Long	0.80	1.50	1.60
Tuen Mun	1.00	1.70	2.00
Tung Chung	0.70	1.25	1.40
Tai Po	0.75	1.20	1.50
Sha Tin	0.70	1.25	1.50
North	NA	NA	NA
Tap Mun	0.23	1.25	1.40

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

Roadside

Station	NO₂	PM₁₀	PM_2.5
Causeway Bay	1.70	1.80	2.20
Central	1.70	1.45	1.70
Mong Kok	1.85	1.45	1.80

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):