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
Aston Hill
92
Low (3)
6
Low (1)
Not measured Not measured Not measured
Bridgend Park Street
Not measured 27
Low (1)
Not measured Not measured 11
Low (1)
Caerphilly Blackwood High Street
Not measured 25
Low (1)
Not measured Not measured 14
Low (1)
Caerphilly Fochriw
Not measured Not measured Not measured 5
Low (1)
No Data
Caerphilly Islwyn Road Wattsville
Not measured 21
Low (1)
Not measured Not measured Not measured
Caerphilly White Street
Not measured 36
Low (1)
Not measured Not measured 7
Low (1)
Cardiff Castle Street
Not measured 91
Low (2)
Not measured 9
Low (1)
14
Low (1)
Cardiff Centre
68
Low (3)
39
Low (1)
5
Low (1)
8
Low (1)
9
Low (1)
Cardiff Newport Road
Not measured 44
Low (1)
Not measured Not measured 12
Low (1)
Chepstow A48
Not measured 42
Low (1)
Not measured 7
Low (1)
9
Low (1)
Cimla Road / Victoria Gardens
Not measured 30
Low (1)
Not measured Not measured Not measured
Cwmbran Crownbridge
84
Low (3)
11
Low (1)
Not measured Not measured 11
Low (1)
Hafod-yr-ynys Hill Roadside
Not measured 28
Low (1)
Not measured Not measured Not measured
Marchlyn Mawr
No Data 2
Low (1)
Not measured Not measured Not measured
Nantgarw Road
Not measured 22
Low (1)
Not measured Not measured Not measured
Narberth
82
Low (3)
2
Low (1)
1
Low (1)
3
Low (1)
5
Low (1)
Newport M4 Junction 25
50
Low (2)
106
Low (2)
Not measured Not measured Not measured
Newport St Julians Comp School
Not measured 22
Low (1)
Not measured 5
Low (1)
9
Low (1)
Port Talbot Dyffryn School
Not measured Not measured Not measured 8
Low (1)
14
Low (1)
Port Talbot Little Warren
Not measured Not measured Not measured 8
Low (1)
11
Low (1)
Port Talbot Margam
83
Low (3)
19
Low (1)
36
Low (1)
6
Low (1)
18
Low (2)
Port Talbot Prince Street 2
Not measured Not measured Not measured 7
Low (1)
15
Low (1)
Port Talbot Twll-yn-y-Wal Park
Not measured Not measured Not measured Not measured No Data
Rhondda Glyncoch Garth Avenue
Not measured Not measured Not measured 6
Low (1)
8
Low (1)
Rhondda Mountain Ash
Not measured 54
Low (1)
Not measured Not measured Not measured
Rhondda Pontypridd Gelliwastad Rd
Not measured No Data Not measured Not measured Not measured
Rhondda-Cynon-Taf Broadway
Not measured 36
Low (1)
Not measured Not measured Not measured
Swansea Cwm Level Park
No Data No Data Not measured Not measured Not measured
Swansea Hafod DOAS
77
Low (3)
68
Low (2)
Not measured Not measured Not measured
Swansea Morfa Road NOX
Not measured No Data Not measured Not measured Not measured
Swansea Morriston Roadside
No Data No Data Not measured No Data Not measured
Swansea Port Tennant Roadside
Not measured No Data Not measured No Data Not measured
Swansea Roadside
Not measured 40
Low (1)
Not measured 6
Low (1)
12
Low (1)
Swansea St Thomas DOAS
87
Low (3)
82
Low (2)
6
Low (1)
Not measured Not measured
Swansea Station Court High Street
Not measured No Data Not measured Not measured Not measured
Twynyrodyn
Not measured Not measured Not measured No Data No Data
Wrexham
Not measured 19
Low (1)
3
Low (1)
6
Low (1)
8
Low (1)
Wrexham Chirk
Not measured 22
Low (1)
Not measured 2
Low (1)
9
Low (1)
Wrexham Chirk Community Hospital
Not measured 13
Low (1)
Not measured 3
Low (1)
10
Low (1)