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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 14 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 6(4) 19(19) 21(-) 29(12) 0.4(4) 9(36)
South 8(5) 23(23) 15(-) 32(14) 0.4(4) 9(39)
East 7(4) 18(18) 11(-) 48(20) 0.3(3) 10(40)
West 2(1) 23(23) 13(-) 48(20) 0.4(4) 10(41)
Central 4(3) 20(20) 20(-) 36(15) 0.3(3) 7(30)

1-hr PM2.5 (µg/m3)b Readings on 14 Jan 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 13 19 9 7 6 5 5 7 10 12 11 11
South 3 4 6 2 4 7 2 14 11 15 21 17
East 10 5 10 5 10 9 10 11 9 12 14 9
West 9 6 6 9 4 6 15 12 9 14 20 18
Central 3 2 4 4 4 7 4 9 3 2 12 13
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 7 9 7 5 6 5 8 12 10 12 8 -
South 13 16 9 14 13 6 10 7 9 10 9 -
East 9 8 7 10 10 10 13 9 8 14 11 -
West 12 17 11 8 5 11 7 8 8 6 9 -
Central 11 10 9 7 9 13 8 9 6 9 10 -

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 14 Jan 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 25 27 30 27 25 25 27 33 36 41 49 53
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 52 50 43 41 36 36 37 38 37 38 39 -

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.