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 No data No data
Anglesey Felin Cafnan
No data No data No data 14
Low (2)
24
Low (2)
Anglesey Llynfaes
No data No data No data 7
Low (1)
14
Low (1)
Anglesey Penhesgyn 3
No data No data No data 6
Low (1)
12
Low (1)
Aston Hill
81
Low (3)
10
Low (1)
No data No data No data
Caerphilly Blackwood High Street
No data 100
Low (2)
No data No data 11
Low (1)
Caerphilly Fochriw
No data No data No data 10
Low (1)
12
Low (1)
Caerphilly Islwyn Road Wattsville
No data 41
Low (1)
No data No data No data
Caerphilly White Street
No data 137
Low (3)
No data No data 25
Low (2)
Cardiff Centre
45
Low (2)
34
Low (1)
4
Low (1)
20
Low (2)
22
Low (2)
Cardiff Newport Road
No data 87
Low (2)
No data No data 27
Low (2)
Chepstow A48
No data 64
Low (1)
No data 17
Low (2)
23
Low (2)
Cimla Road / Victoria Gardens
No data 66
Low (1)
No data No data No data
Cwmbran
59
Low (2)
21
Low (1)
No data No data 13
Low (1)
Hafod-yr-ynys Roadside
No data 163
Low (3)
No data No data No data
Marchlyn Mawr
No data No data No data No data No data
Nantgarw Road
No data 77
Low (2)
No data No data No data
Narberth
86
Low (3)
8
Low (1)
10
Low (1)
No data 21
Low (2)
Newport M4 Junction 25
27
Low (1)
72
Low (2)
No data No data No data
Newport St Julians Comp School
No data 59
Low (1)
No data No data No data
Port Talbot Docks
No data No data No data No data 21
Low (2)
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 27
Low (2)
Port Talbot Margam
82
Low (3)
40
Low (1)
1
Low (1)
17
Low (2)
25
Low (2)
Port Talbot Prince Street 2
No data No data No data 15
Low (2)
23
Low (2)
Port Talbot Talbot Road
No data No data No data No data 27
Low (2)
Port Talbot Theodore Road
No data No data No data No data 18
Low (2)
Port Talbot Twll-yn-y-Wal Park
No data No data No data No data 25
Low (2)
Rhondda Glyncoch Garth Avenue
No data No data No data No data 29
Low (2)
Rhondda Mountain Ash
No data 96
Low (2)
No data No data No data
Rhondda Pontypridd Gelliwastad Rd
No data 55
Low (1)
No data No data No data
Rhondda-Cynon-Taf Broadway
No data 49
Low (1)
No data No data No data
Swansea Cwm Level Park
54
Low (2)
41
Low (1)
No data No data No data
Swansea Hafod DOAS
50
Low (2)
81
Low (2)
No data No data No data
Swansea Morfa Road NOX
No data 71
Low (2)
No data No data No data
Swansea Morriston Roadside
No data No data No data No data No data
Swansea Roadside
No data 52
Low (1)
No data 20
Low (2)
26
Low (2)
Swansea St Thomas DOAS
57
Low (2)
67
Low (1)
9
Low (1)
No data No data
Swansea Station Court High Street
No data 100
Low (2)
No data No data No data
Twynyrodyn
No data No data No data No data No data
V Glamorgan Windsor Road Penarth
6
Low (1)
72
Low (2)
No data No data 26
Low (2)
Wrexham
No data 60
Low (1)
10
Low (1)
No data No data