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 2
Low (1)
4
Low (1)
Anglesey Llynfaes
Not measured Not measured Not measured 3
Low (1)
8
Low (1)
Anglesey Penhesgyn 3
Not measured Not measured Not measured 3
Low (1)
7
Low (1)
Aston Hill
59
Low (2)
14
Low (1)
Not measured Not measured Not measured
Caerphilly Blackwood High Street
Not measured No Data Not measured Not measured 18
Low (2)
Caerphilly Fochriw
Not measured Not measured Not measured 9
Low (1)
8
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured 53
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 129
Low (2)
Not measured Not measured 30
Low (2)
Cardiff Centre
25
Low (1)
151
Low (3)
6
Low (1)
17
Low (2)
31
Low (2)
Cardiff Newport Road
Not measured 106
Low (2)
Not measured Not measured 37
Low (3)
Chepstow A48
Not measured 66
Low (1)
Not measured 15
Low (2)
18
Low (2)
Cimla Road / Victoria Gardens
Not measured Not measured Not measured Not measured Not measured
Cwmbran
48
Low (2)
62
Low (1)
Not measured Not measured 20
Low (2)
Hafod-yr-ynys Roadside
Not measured 165
Low (3)
Not measured Not measured Not measured
Marchlyn Mawr
Not measured Not measured Not measured Not measured Not measured
Nantgarw Road
Not measured 70
Low (2)
Not measured Not measured Not measured
Narberth
51
Low (2)
15
Low (1)
4
Low (1)
6
Low (1)
9
Low (1)
Newport M4 Junction 25
23
Low (1)
63
Low (1)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 97
Low (2)
Not measured 13
Low (2)
17
Low (2)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured 17
Low (2)
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 32
Low (2)
Port Talbot Margam
42
Low (2)
53
Low (1)
3
Low (1)
9
Low (1)
14
Low (1)
Port Talbot Prince Street 2
Not measured Not measured Not measured Not measured Not measured
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured 14
Low (1)
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured 16
Low (1)
Rhondda Mountain Ash
Not measured 138
Low (3)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 115
Low (2)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 46
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
26
Low (1)
49
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
39
Low (2)
120
Low (2)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured Not measured Not measured Not measured Not measured
Swansea Morriston Roadside
Not measured Not measured Not measured Not measured Not measured
Swansea Roadside
Not measured 86
Low (2)
Not measured 8
Low (1)
12
Low (1)
Swansea St Thomas DOAS
44
Low (2)
98
Low (2)
33
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 112
Low (2)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured Not measured Not measured
V Glamorgan Windsor Road Penarth
27
Low (1)
56
Low (1)
Not measured Not measured 22
Low (2)
Wrexham
Not measured 64
Low (1)
7
Low (1)
14
Low (2)
17
Low (2)