24 Hour Summary

The maximum pollutant concentrations measured during the last 24 hours across Wales are shown below. Summary graphs showing the last seven days are available for each pollutant in the left hand column of the table.

Site 8 Hour mean
Ozone
µgm-3
Hourly mean
Nitrogen dioxide
µgm-3
Max 15 min mean
Sulphur dioxide
µgm-3
Running 24 Hour mean
PM2.5
Particles
µgm-3
Running 24 Hour mean
PM10
Particles
µgm-3
Anglesey Brynteg
Not measured Not measured Not measured 1
Low (1)
2
Low (1)
Anglesey Felin Cafnan
Not measured Not measured Not measured 2
Low (1)
4
Low (1)
Anglesey Llynfaes
Not measured Not measured Not measured 2
Low (1)
3
Low (1)
Anglesey Penhesgyn 3
Not measured Not measured Not measured 1
Low (1)
2
Low (1)
Aston Hill
62
Low (2)
16
Low (1)
Not measured Not measured Not measured
Caerphilly Blackwood High Street
Not measured 59
Low (1)
Not measured Not measured 12
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured No Data No Data
Caerphilly Islwyn Road Wattsville
Not measured 56
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 61
Low (1)
Not measured Not measured 16
Low (1)
Cardiff Centre
48
Low (2)
37
Low (1)
3
Low (1)
9
Low (1)
12
Low (1)
Cardiff Newport Road
Not measured 78
Low (2)
Not measured Not measured 19
Low (2)
Chepstow A48
Not measured 73
Low (2)
Not measured 11
Low (1)
14
Low (1)
Cimla Road / Victoria Gardens
Not measured 75
Low (2)
Not measured Not measured Not measured
Cwmbran
55
Low (2)
34
Low (1)
Not measured Not measured 10
Low (1)
Hafod-yr-ynys Roadside
Not measured 126
Low (2)
Not measured Not measured Not measured
Marchlyn Mawr
No Data No Data Not measured Not measured Not measured
Nantgarw Road
Not measured 51
Low (1)
Not measured Not measured Not measured
Narberth
69
Low (3)
7
Low (1)
12
Low (1)
2
Low (1)
3
Low (1)
Newport M4 Junction 25
39
Low (2)
90
Low (2)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 59
Low (1)
Not measured 10
Low (1)
14
Low (1)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured 3289
Very High (10)
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 21
Low (2)
Port Talbot Margam
55
Low (2)
53
Low (1)
2
Low (1)
12
Low (2)
15
Low (1)
Port Talbot Prince Street 2
Not measured Not measured Not measured 8
Low (1)
10
Low (1)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured 12
Low (1)
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured No Data
Rhondda Mountain Ash
Not measured 90
Low (2)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 87
Low (2)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 72
Low (2)
Not measured Not measured Not measured
Swansea Cwm Level Park
53
Low (2)
45
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
58
Low (2)
104
Low (2)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured 79
Low (2)
Not measured Not measured Not measured
Swansea Morriston Roadside
No Data No Data Not measured No Data Not measured
Swansea Roadside
Not measured 92
Low (2)
Not measured 12
Low (2)
13
Low (1)
Swansea St Thomas DOAS
72
Low (3)
89
Low (2)
44
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 125
Low (2)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured No Data No Data
V Glamorgan Windsor Road Penarth
46
Low (2)
47
Low (1)
Not measured Not measured 16
Low (1)
Wrexham
Not measured No Data No Data No Data No Data