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 No Data No Data
Anglesey Felin Cafnan
Not measured Not measured Not measured 5
Low (1)
9
Low (1)
Anglesey Llynfaes
Not measured Not measured Not measured 5
Low (1)
8
Low (1)
Anglesey Penhesgyn 3
Not measured Not measured Not measured 5
Low (1)
7
Low (1)
Aston Hill
53
Low (2)
15
Low (1)
Not measured Not measured Not measured
Caerphilly Blackwood High Street
Not measured 25
Low (1)
Not measured Not measured 16
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured 9
Low (1)
12
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured 30
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 46
Low (1)
Not measured Not measured 18
Low (2)
Cardiff Centre
37
Low (2)
47
Low (1)
2
Low (1)
16
Low (2)
19
Low (2)
Cardiff Newport Road
Not measured 81
Low (2)
Not measured Not measured 23
Low (2)
Chepstow A48
Not measured 76
Low (2)
Not measured 15
Low (2)
23
Low (2)
Cimla Road / Victoria Gardens
Not measured 62
Low (1)
Not measured Not measured Not measured
Cwmbran
46
Low (2)
41
Low (1)
Not measured Not measured 15
Low (1)
Hafod-yr-ynys Roadside
Not measured 142
Low (3)
Not measured Not measured Not measured
Marchlyn Mawr
No Data No Data Not measured Not measured Not measured
Nantgarw Road
Not measured 34
Low (1)
Not measured Not measured Not measured
Narberth
51
Low (2)
19
Low (1)
17
Low (1)
14
Low (2)
16
Low (1)
Newport M4 Junction 25
35
Low (2)
36
Low (1)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 42
Low (1)
Not measured 16
Low (2)
19
Low (2)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured No Data
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 28
Low (2)
Port Talbot Margam
50
Low (2)
20
Low (1)
1
Low (1)
14
Low (2)
17
Low (2)
Port Talbot Prince Street 2
Not measured Not measured Not measured 11
Low (1)
14
Low (1)
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 No Data
Rhondda Mountain Ash
Not measured 73
Low (2)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 49
Low (1)
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
42
Low (2)
33
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
43
Low (2)
68
Low (2)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured 52
Low (1)
Not measured Not measured Not measured
Swansea Morriston Roadside
No Data No Data Not measured No Data Not measured
Swansea Roadside
Not measured 52
Low (1)
Not measured 13
Low (2)
19
Low (2)
Swansea St Thomas DOAS
59
Low (2)
61
Low (1)
31
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 71
Low (2)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured No Data No Data
V Glamorgan Windsor Road Penarth
No Data 15
Low (1)
Not measured Not measured No Data
Wrexham
Not measured 56
Low (1)
6
Low (1)
14
Low (2)
16
Low (1)