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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 10 Nov 2014

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 9(6) 40(40) 46(-) 24(10) 0.3(3) 22(62)
South 13(8) 33(33) 39(-) 33(14) 0.5(5) 23(64)
East 11(7) 31(31) 28(-) 37(16) 0.5(5) 24(65)
West 22(14) 39(39) 55(-) 38(16) 0.5(5) 27(68)
Central 15(10) 31(31) 55(-) 48(20) 0.6(6) 21(61)

1-hr PM2.5 (µg/m3)b Readings on 10 Nov 2014

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 17 25 20 22 19 29 28 31 25 29 35 25
South 20 17 23 41 22 30 25 28 39 40 47 8
East 27 26 29 31 34 39 35 36 50 42 33 6
West 23 19 27 31 31 32 20 34 25 26 35 28
Central 16 22 26 29 23 28 26 32 32 31 38 7
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 12 11 11 16 22 18 23 26 25 17 16 -
South 17 28 30 34 36 29 6 5 4 7 7 -
East 15 14 25 23 21 26 16 15 9 7 10 -
West 40 26 26 29 37 31 23 22 18 17 16 -
Central 10 9 21 26 21 29 19 14 15 4 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 10 Nov 2014

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 59 61 63 67 68 71 69 71 72 75 77 70
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 64 57 59 62 66 67 64 60 55 53 51 -

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.