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 6
Low (1)
13
Low (1)
Anglesey Llynfaes
Not measured Not measured Not measured 9
Low (1)
15
Low (1)
Anglesey Penhesgyn 3
Not measured Not measured Not measured 7
Low (1)
11
Low (1)
Aston Hill
69
Low (3)
2
Low (1)
Not measured Not measured Not measured
Caerphilly Blackwood High Street
Not measured 25
Low (1)
Not measured Not measured 13
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured 2
Low (1)
5
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured 32
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 22
Low (1)
Not measured Not measured 19
Low (2)
Cardiff Centre
48
Low (2)
12
Low (1)
5
Low (1)
9
Low (1)
12
Low (1)
Cardiff Newport Road
Not measured 18
Low (1)
Not measured Not measured 9
Low (1)
Chepstow A48
Not measured 97
Low (2)
Not measured 13
Low (2)
17
Low (2)
Cimla Road / Victoria Gardens
Not measured 34
Low (1)
Not measured Not measured Not measured
Cwmbran
60
Low (2)
5
Low (1)
Not measured Not measured 12
Low (1)
Hafod-yr-ynys Roadside
Not measured 60
Low (1)
Not measured Not measured Not measured
Marchlyn Mawr
No Data No Data Not measured Not measured Not measured
Nantgarw Road
Not measured 19
Low (1)
Not measured Not measured Not measured
Narberth
37
Low (2)
8
Low (1)
1
Low (1)
4
Low (1)
7
Low (1)
Newport M4 Junction 25
27
Low (1)
22
Low (1)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 15
Low (1)
Not measured 7
Low (1)
13
Low (1)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured 3
Low (1)
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 11
Low (1)
Port Talbot Margam
56
Low (2)
21
Low (1)
2
Low (1)
8
Low (1)
16
Low (1)
Port Talbot Prince Street 2
Not measured Not measured Not measured 16
Low (2)
39
Low (3)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured 12
Low (1)
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured No Data
Rhondda Mountain Ash
Not measured 32
Low (1)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 59
Low (1)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 18
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
58
Low (2)
8
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
65
Low (2)
30
Low (1)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured 24
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 18
Low (1)
Not measured 12
Low (2)
12
Low (1)
Swansea St Thomas DOAS
74
Low (3)
53
Low (1)
2
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 46
Low (1)
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 12
Low (1)
Wrexham
Not measured 3
Low (1)
No Data 4
Low (1)
7
Low (1)