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 3
Low (1)
16
Low (1)
Anglesey Llynfaes
Not measured Not measured Not measured 4
Low (1)
17
Low (2)
Anglesey Penhesgyn 3
Not measured Not measured Not measured 3
Low (1)
10
Low (1)
Aston Hill
88
Low (3)
4
Low (1)
Not measured Not measured Not measured
Caerphilly Blackwood High Street
Not measured Not measured Not measured Not measured Not measured
Caerphilly Fochriw
Not measured Not measured Not measured 7
Low (1)
15
Low (1)
Caerphilly Islwyn Road Wattsville
Not measured Not measured Not measured Not measured Not measured
Caerphilly White Street
Not measured 92
Low (2)
Not measured Not measured 25
Low (2)
Cardiff Centre
88
Low (3)
47
Low (1)
6
Low (1)
5
Low (1)
14
Low (1)
Cardiff Newport Road
Not measured 48
Low (1)
Not measured Not measured 18
Low (2)
Chepstow A48
Not measured 55
Low (1)
Not measured No Data No Data
Cimla Road / Victoria Gardens
Not measured 56
Low (1)
Not measured Not measured Not measured
Cwmbran
97
Low (3)
33
Low (1)
Not measured Not measured 27
Low (2)
Hafod-yr-ynys Roadside
Not measured 143
Low (3)
Not measured Not measured Not measured
Marchlyn Mawr
Not measured Not measured Not measured Not measured Not measured
Nantgarw Road
Not measured 54
Low (1)
Not measured Not measured Not measured
Narberth
62
Low (2)
6
Low (1)
6
Low (1)
7
Low (1)
11
Low (1)
Newport M4 Junction 25
45
Low (2)
68
Low (2)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 39
Low (1)
Not measured 11
Low (1)
25
Low (2)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured 28
Low (2)
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 21
Low (2)
Port Talbot Margam
79
Low (3)
33
Low (1)
23
Low (1)
17
Low (2)
35
Low (3)
Port Talbot Prince Street 2
Not measured Not measured Not measured 13
Low (2)
29
Low (2)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured 32
Low (2)
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured Not measured
Rhondda Mountain Ash
Not measured 76
Low (2)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 43
Low (1)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 61
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
88
Low (3)
21
Low (1)
Not measured Not measured Not measured
Swansea Hafod DOAS
75
Low (3)
56
Low (1)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured 43
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 39
Low (1)
Not measured 26
Low (3)
25
Low (2)
Swansea St Thomas DOAS
80
Low (3)
54
Low (1)
32
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured 70
Low (2)
Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured Not measured Not measured
V Glamorgan Windsor Road Penarth
65
Low (2)
524
High (8)
Not measured Not measured 24
Low (2)
Wrexham
Not measured 40
Low (1)
3
Low (1)
8
Low (1)
13
Low (1)