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 Not measured Not measured
Anglesey Llynfaes
Not measured Not measured Not measured 14
Low (2)
24
Low (2)
Anglesey Penhesgyn 3
Not measured Not measured Not measured 8
Low (1)
13
Low (1)
Aston Hill
73
Low (3)
10
Low (1)
Not measured Not measured Not measured
Bridgend Park Street
Not measured Not measured Not measured Not measured Not measured
Caerphilly Blackwood High Street
Not measured 29
Low (1)
Not measured Not measured 34
Low (3)
Caerphilly Fochriw
Not measured Not measured Not measured Not measured Not measured
Caerphilly Islwyn Road Wattsville
Not measured 29
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 43
Low (1)
Not measured Not measured 24
Low (2)
Cardiff Castle Street
Not measured 47
Low (1)
Not measured 16
Low (2)
24
Low (2)
Cardiff Centre
64
Low (2)
36
Low (1)
7
Low (1)
15
Low (2)
19
Low (2)
Cardiff Newport Road
Not measured 51
Low (1)
Not measured Not measured 28
Low (2)
Chepstow A48
Not measured 29
Low (1)
Not measured 20
Low (2)
23
Low (2)
Cimla Road / Victoria Gardens
Not measured 70
Low (2)
Not measured Not measured Not measured
Cwmbran Crownbridge
70
Low (3)
21
Low (1)
Not measured Not measured 17
Low (2)
Hafod-yr-ynys Roadside
Not measured 74
Low (2)
Not measured Not measured Not measured
Marchlyn Mawr
80
Low (3)
3
Low (1)
Not measured Not measured Not measured
Nantgarw Road
Not measured 49
Low (1)
Not measured Not measured Not measured
Narberth
68
Low (3)
6
Low (1)
No Data 11
Low (1)
14
Low (1)
Newport M4 Junction 25
48
Low (2)
45
Low (1)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 25
Low (1)
Not measured 13
Low (2)
17
Low (2)
Port Talbot Dyffryn School
Not measured Not measured Not measured Not measured Not measured
Port Talbot Little Warren
Not measured Not measured Not measured Not measured 21
Low (2)
Port Talbot Margam
64
Low (2)
64
Low (1)
2
Low (1)
19
Low (2)
35
Low (3)
Port Talbot Prince Street 2
Not measured Not measured Not measured 19
Low (2)
38
Low (3)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured 35
Low (3)
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured Not measured 15
Low (1)
Rhondda Mountain Ash
Not measured 50
Low (1)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured 69
Low (2)
Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 38
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
Not measured Not measured Not measured Not measured Not measured
Swansea Hafod DOAS
Not measured Not measured Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured Not measured Not measured Not measured Not measured
Swansea Morriston Roadside
Not measured Not measured Not measured Not measured Not measured
Swansea Port Tennant Roadside
Not measured Not measured Not measured Not measured Not measured
Swansea Roadside
Not measured 59
Low (1)
Not measured 19
Low (2)
31
Low (2)
Swansea St Thomas DOAS
Not measured Not measured Not measured Not measured Not measured
Swansea Station Court High Street
Not measured Not measured Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured Not measured Not measured
Wrexham
Not measured 53
Low (1)
7
Low (1)
23
Low (2)
30
Low (2)
Wrexham Chirk
Not measured 61
Low (1)
Not measured No Data No Data