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
58
Low (2)
1
Low (1)
Not measured Not measured Not measured
Bridgend Park Street
Not measured 34
Low (1)
Not measured Not measured 17
Low (2)
Caerphilly Blackwood High Street
Not measured 30
Low (1)
Not measured Not measured No Data
Caerphilly Fochriw
Not measured Not measured Not measured 3
Low (1)
5
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured 55
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 29
Low (1)
Not measured Not measured 13
Low (1)
Cardiff Castle Street
Not measured 33
Low (1)
Not measured 4
Low (1)
11
Low (1)
Cardiff Centre
74
Low (3)
18
Low (1)
6
Low (1)
5
Low (1)
11
Low (1)
Cardiff Newport Road
Not measured 16
Low (1)
Not measured Not measured 10
Low (1)
Chepstow A48
Not measured 76
Low (2)
Not measured 7
Low (1)
14
Low (1)
Cimla Road / Victoria Gardens
Not measured 57
Low (1)
Not measured Not measured Not measured
Cwmbran Crownbridge
73
Low (3)
6
Low (1)
Not measured Not measured 7
Low (1)
Hafod-yr-ynys Roadside
Not measured Not measured Not measured Not measured Not measured
Marchlyn Mawr
73
Low (3)
2
Low (1)
Not measured Not measured Not measured
Nantgarw Road
Not measured 49
Low (1)
Not measured Not measured Not measured
Narberth
77
Low (3)
4
Low (1)
1
Low (1)
4
Low (1)
8
Low (1)
Newport M4 Junction 25
62
Low (2)
80
Low (2)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 40
Low (1)
Not measured 5
Low (1)
8
Low (1)
Port Talbot Dyffryn School
Not measured Not measured Not measured 6
Low (1)
19
Low (2)
Port Talbot Little Warren
Not measured Not measured Not measured 5
Low (1)
32
Low (2)
Port Talbot Margam
79
Low (3)
11
Low (1)
No Data 5
Low (1)
21
Low (2)
Port Talbot Prince Street 2
Not measured Not measured Not measured 13
Low (2)
49
Low (3)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured Not measured
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured Not measured
Rhondda Mountain Ash
Not measured 58
Low (1)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 68
Low (2)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 39
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
Not measured Not measured Not measured Not measured Not measured
Swansea Hafod DOAS
84
Low (3)
26
Low (1)
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 Port Tennant Roadside
Not measured 53
Low (1)
Not measured 1
Low (1)
Not measured
Swansea Roadside
Not measured 25
Low (1)
Not measured 6
Low (1)
12
Low (1)
Swansea St Thomas DOAS
71
Low (3)
25
Low (1)
1
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 79
Low (2)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured Not measured Not measured
Wrexham
Not measured 21
Low (1)
44
Low (1)
3
Low (1)
5
Low (1)
Wrexham Chirk
Not measured 42
Low (1)
Not measured 4
Low (1)
8
Low (1)
Wrexham Chirk Community Hospital
Not measured 43
Low (1)
Not measured 3
Low (1)
5
Low (1)