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Pollutant Concentrations

Air quality readings will be available hourly from 7am to 11pm. Air quality readings from 12am to 6am will be made available at 7am on the same day.

 

Readings on 11 Jan 2015

View reading for:

Region 24-hr Sulphur dioxide
(µg/m3) 		24-hr PM10
(µg/m3) 		1-hr Nitrogen dioxide
(µg/m3)a 		8-hr Ozone
(µg/m3) 		8-hr Carbon monoxide
(mg/m3) 		24-hr PM2.5
(µg/m3)
North 10(6) 19(19) 20(-) 17(7) 0.4(4) 9(36)
South 5(3) 18(18) 14(-) 18(8) 0.3(3) 9(39)
East 8(5) 20(20) 13(-) 32(13) 0.3(3) 13(51)
West 7(4) 20(20) 5(-) 27(11) 0.5(5) 9(38)
Central 7(4) 16(16) 22(-) 29(12) 0.3(3) 7(28)

1-hr PM2.5 (µg/m3)b Readings on 11 Jan 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 10 10 5 9 12 8 13 6 12 15 18 6
South 3 3 8 3 7 5 8 13 13 11 17 17
East 15 11 15 14 11 24 24 22 10 17 24 21
West 10 4 10 11 5 11 7 9 9 9 15 9
Central 4 6 5 3 4 8 4 8 8 4 8 12
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 4 8 8 10 10 7 6 6 9 5 11 -
South 17 14 12 13 13 4 14 10 8 6 7 -
East 8 9 6 6 6 8 6 7 8 8 9 -
West 12 13 10 9 9 13 6 8 5 9 7 -
Central 11 7 6 8 8 5 8 9 5 4 9 -

Note:
a Sub-index for nitrogen dioxide is reported only when the 1-hr concentration equals or exceeds 1130 µg/m3.

b There is no sub-index for 1-hr PM2.5.

3-hr PSI Readings from 1am to 12am on 11 Jan 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 31 31 33 32 33 37 41 47 47 47 52 53
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 52 47 40 39 34 33 32 33 32 30 30 -

Hourly updates of 3-hr PSI readings are provided from 7am to 11pm. The 3-hr PSI readings from 12am to 6am will be made available at 7am on the same day. The 3-hr PSI readings are calculated based on PM2.5 concentrations only.

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