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Pollutant Concentrations

Readings on 28 May 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 3(2) 23(23) 26(-) 7(3) 0.4(4) 13(52)
South 7(5) 22(22) 21(-) 11(5) 0.3(3) 14(53)
East 11(7) 18(18) 17(-) 18(8) 0.5(5) 12(49)
West 33(21) 30(30) 27(-) 9(4) 0.3(3) 15(54)
Central 7(4) 24(24) 31(-) 11(5) 0.5(5) 13(51)

1-hr PM2.5 (µg/m3)b Readings on 27 May 2015

View reading for:

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
North 11 10 7 15 22 18 22 18 12 21 16 15
South 31 25 15 11 11 14 15 17 14 9 13 16
East 20 15 25 17 18 13 10 13 8 7 19 11
West 19 29 15 9 14 12 13 20 20 19 16 21
Central 22 17 16 18 15 13 16 14 23 15 11 7
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
North 17 11 15 14 12 12 9 9 7 10 7 9
South 18 13 12 20 16 11 18 12 10 7 2 5
East 10 12 10 10 11 11 7 15 5 7 4 6
West 24 20 23 14 8 10 15 11 9 9 6 6
Central 11 13 18 14 9 8 5 12 7 4 7 5

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 27 May 2015

Time 1am 2am 3am 4am 5am 6am 7am 8am 9am 10am 11am 12pm
3-hr PSI 60 60 58 56 55 54 54 54 55 55 54 54
Time 1pm 2pm 3pm 4pm 5pm 6pm 7pm 8pm 9pm 10pm 11pm 12am
3-hr PSI 54 54 54 54 53 50 45 46 42 37 28 26



The real-time data is automatically published as soon as it is generated by our air monitoring stations. The data is subject to verification and correction subsequently if necessary.