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
No data No data No data 4
Low (1)
11
Low (1)
Anglesey Felin Cafnan
No data No data No data 5
Low (1)
10
Low (1)
Anglesey Llynfaes
No data No data No data 5
Low (1)
15
Low (1)
Anglesey Penhesgyn 3
No data No data No data 4
Low (1)
13
Low (1)
Aston Hill
66
Low (2)
3
Low (1)
No data No data No data
Caerphilly Blackwood High Street
No data 62
Low (1)
No data No data 12
Low (1)
Caerphilly Fochriw
No data No data No data 7
Low (1)
12
Low (1)
Caerphilly Islwyn Road Wattsville
No data 39
Low (1)
No data No data No data
Caerphilly White Street
No data 57
Low (1)
No data No data 14
Low (1)
Cardiff Centre
34
Low (2)
15
Low (1)
No data 5
Low (1)
9
Low (1)
Cardiff Newport Road
No data 22
Low (1)
No data No data 14
Low (1)
Chepstow A48
No data 52
Low (1)
No data 6
Low (1)
13
Low (1)
Cimla Road / Victoria Gardens
No data 63
Low (1)
No data No data No data
Cwmbran
62
Low (2)
13
Low (1)
No data No data 16
Low (1)
Hafod-yr-ynys Roadside
No data 141
Low (3)
No data No data No data
Marchlyn Mawr
No data No data No data No data No data
Nantgarw Road
No data 52
Low (1)
No data No data No data
Narberth
53
Low (2)
9
Low (1)
6
Low (1)
4
Low (1)
7
Low (1)
Newport M4 Junction 25
32
Low (1)
63
Low (1)
No data No data No data
Newport St Julians Comp School
No data 35
Low (1)
No data 5
Low (1)
11
Low (1)
Port Talbot Dyffryn School
No data No data No data No data No data
Port Talbot Little Warren
No data No data No data No data 13
Low (1)
Port Talbot Margam
60
Low (2)
21
Low (1)
6
Low (1)
9
Low (1)
28
Low (2)
Port Talbot Prince Street 2
No data No data No data 7
Low (1)
30
Low (2)
Port Talbot Twll-yn-y-Wal Park
No data No data No data No data 15
Low (1)
Rhondda Glyncoch Garth Avenue
No data No data No data No data 37
Low (3)
Rhondda Mountain Ash
No data 78
Low (2)
No data No data No data
Rhondda Pontypridd Gelliwastad Rd
No data 73
Low (2)
No data No data No data
Rhondda-Cynon-Taf Broadway
No data 42
Low (1)
No data No data No data
Swansea Cwm Level Park
62
Low (2)
30
Low (1)
No data No data No data
Swansea Hafod DOAS
53
Low (2)
61
Low (1)
No data No data No data
Swansea Morfa Road NOX
No data No data No data No data No data
Swansea Morriston Roadside
No data No data No data No data No data
Swansea Roadside
No data 46
Low (1)
No data 15
Low (2)
17
Low (2)
Swansea St Thomas DOAS
85
Low (3)
55
Low (1)
2
Low (1)
No data No data
Swansea Station Court High Street
No data 79
Low (2)
No data No data No data
Twynyrodyn
No data No data No data No data No data
V Glamorgan Windsor Road Penarth
35
Low (2)
28
Low (1)
No data No data 14
Low (1)
Wrexham
No data 34
Low (1)
2
Low (1)
No data No data