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 5
Low (1)
20
Low (2)
Anglesey Llynfaes
Not measured Not measured Not measured 7
Low (1)
29
Low (2)
Anglesey Penhesgyn 3
Not measured Not measured Not measured 5
Low (1)
13
Low (1)
Aston Hill
61
Low (2)
2
Low (1)
Not measured Not measured Not measured
Caerphilly Blackwood High Street
Not measured 45
Low (1)
Not measured Not measured 15
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured 7
Low (1)
14
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured Not measured Not measured Not measured Not measured
Caerphilly White Street
Not measured 50
Low (1)
Not measured Not measured 18
Low (2)
Cardiff Centre
55
Low (2)
40
Low (1)
6
Low (1)
No Data No Data
Cardiff Newport Road
Not measured 23
Low (1)
Not measured Not measured No Data
Chepstow A48
Not measured 38
Low (1)
Not measured 10
Low (1)
18
Low (2)
Cimla Road / Victoria Gardens
Not measured 41
Low (1)
Not measured Not measured Not measured
Cwmbran
76
Low (3)
8
Low (1)
Not measured Not measured 20
Low (2)
Hafod-yr-ynys Roadside
Not measured 116
Low (2)
Not measured Not measured Not measured
Marchlyn Mawr
Not measured Not measured Not measured Not measured Not measured
Nantgarw Road
Not measured 45
Low (1)
Not measured Not measured Not measured
Narberth
46
Low (2)
5
Low (1)
7
Low (1)
6
Low (1)
11
Low (1)
Newport M4 Junction 25
35
Low (2)
56
Low (1)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 19
Low (1)
Not measured 9
Low (1)
23
Low (2)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured 24
Low (2)
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 16
Low (1)
Port Talbot Margam
57
Low (2)
22
Low (1)
13
Low (1)
11
Low (1)
27
Low (2)
Port Talbot Prince Street 2
Not measured Not measured Not measured 10
Low (1)
41
Low (3)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured 26
Low (2)
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured Not measured
Rhondda Mountain Ash
Not measured 64
Low (1)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 73
Low (2)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 31
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
60
Low (2)
4
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
62
Low (2)
15
Low (1)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured 27
Low (1)
Not measured Not measured Not measured
Swansea Morriston Roadside
Not measured Not measured Not measured Not measured Not measured
Swansea Roadside
Not measured 19
Low (1)
Not measured No Data No Data
Swansea St Thomas DOAS
67
Low (3)
40
Low (1)
3
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 87
Low (2)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured Not measured Not measured
V Glamorgan Windsor Road Penarth
55
Low (2)
44
Low (1)
Not measured Not measured 24
Low (2)
Wrexham
Not measured 22
Low (1)
2
Low (1)
6
Low (1)
10
Low (1)