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 Not measured Not measured
Anglesey Llynfaes
Not measured Not measured Not measured Not measured Not measured
Anglesey Penhesgyn 3
Not measured Not measured Not measured Not measured Not measured
Aston Hill
73
Low (3)
6
Low (1)
Not measured Not measured Not measured
Bridgend Park Street
Not measured 93
Low (2)
Not measured Not measured 11
Low (1)
Caerphilly Blackwood High Street
Not measured 75
Low (2)
Not measured Not measured 12
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured Not measured Not measured
Caerphilly Islwyn Road Wattsville
Not measured 83
Low (2)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 116
Low (2)
Not measured Not measured 17
Low (2)
Cardiff Castle Street
Not measured 69
Low (2)
Not measured 10
Low (1)
14
Low (1)
Cardiff Centre
52
Low (2)
52
Low (1)
1
Low (1)
7
Low (1)
7
Low (1)
Cardiff Newport Road
Not measured 71
Low (2)
Not measured Not measured 14
Low (1)
Chepstow A48
Not measured 94
Low (2)
Not measured 11
Low (1)
11
Low (1)
Cimla Road / Victoria Gardens
Not measured 85
Low (2)
Not measured Not measured Not measured
Cwmbran Crownbridge
45
Low (2)
61
Low (1)
Not measured Not measured 10
Low (1)
Hafod-yr-ynys Roadside
Not measured 197
Low (3)
Not measured Not measured Not measured
Marchlyn Mawr
70
Low (3)
2
Low (1)
Not measured Not measured Not measured
Nantgarw Road
Not measured 77
Low (2)
Not measured Not measured Not measured
Narberth
71
Low (3)
8
Low (1)
4
Low (1)
2
Low (1)
5
Low (1)
Newport M4 Junction 25
27
Low (1)
106
Low (2)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 74
Low (2)
Not measured 7
Low (1)
9
Low (1)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured Not measured
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 14
Low (1)
Port Talbot Margam
57
Low (2)
52
Low (1)
22
Low (1)
5
Low (1)
No Data
Port Talbot Prince Street 2
Not measured Not measured Not measured 4
Low (1)
9
Low (1)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured 9
Low (1)
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured 28
Low (2)
Rhondda Mountain Ash
Not measured 117
Low (2)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 88
Low (2)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 68
Low (2)
Not measured Not measured Not measured
Swansea Cwm Level Park
72
Low (3)
57
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
56
Low (2)
104
Low (2)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured 72
Low (2)
Not measured Not measured Not measured
Swansea Morriston Roadside
Not measured Not measured Not measured Not measured Not measured
Swansea Port Tennant Roadside
Not measured 82
Low (2)
Not measured 9
Low (1)
Not measured
Swansea Roadside
Not measured 65
Low (1)
Not measured 12
Low (2)
14
Low (1)
Swansea St Thomas DOAS
Not measured Not measured Not measured Not measured Not measured
Swansea Station Court High Street
Not measured 105
Low (2)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured Not measured Not measured
V Glamorgan Windsor Road Penarth
Not measured Not measured Not measured Not measured Not measured
Wrexham
Not measured 48
Low (1)
5
Low (1)
7
Low (1)
9
Low (1)
Wrexham Chirk
Not measured 40
Low (1)
Not measured 1
Low (1)
3
Low (1)