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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 18 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 7(5) 26(26) 23(-) 36(15) 0.4(4) 11(47)
South 9(5) 29(29) 7(-) 42(18) 0.4(4) 11(47)
East 7(4) 24(24) 8(-) 54(23) 0.4(4) 13(52)
West 2(1) 28(28) 11(-) 55(23) 0.4(4) 12(50)
Central 6(4) 26(26) 13(-) 43(18) 0.3(3) 10(40)

1-hr PM2.5 (µg/m3)b Readings on 18 Jan 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 10 12 16 11 13 9 13 10 12 9 14 10
South 5 13 8 13 7 12 5 9 10 13 12 16
East 15 14 17 16 14 13 9 11 11 11 13 10
West 13 15 13 14 13 11 13 9 8 10 15 12
Central 12 11 13 11 11 10 8 7 4 6 3 10
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 9 8 8 11 7 13 16 9 11 15 9 -
South 10 22 19 15 12 9 12 12 9 11 10 -
East 7 14 10 12 10 11 15 16 12 14 18 -
West 14 13 16 11 10 12 13 10 9 9 11 -
Central 3 8 10 12 10 9 17 16 10 10 12 -

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 18 Jan 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 43 47 51 52 52 49 45 42 39 39 42 46
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 44 46 47 51 48 46 49 52 51 48 47 -

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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