Current measured levels are shown in the table below - showing concentrations and, where applicable, the corresponding index and bands.
Current Levels
| 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 Expressway A494 Deeside Updated: 23/12/2025 20:00 |
Not measured | 33 Low (1) |
Not measured | Not measured | Not measured |
| Aston Hill Updated: 23/12/2025 20:00 |
38 Low (2) |
6 Low (1) |
Not measured | Not measured | Not measured |
| Caerphilly Islwyn Road Wattsville Updated: 23/12/2025 20:00 |
Not measured | 8 Low (1) |
Not measured | Not measured | Not measured |
| Caerphilly White Street Updated: 23/12/2025 20:00 |
Not measured | 8 Low (1) |
Not measured | Not measured | No data |
| Cardiff Castle Street Updated: 08/11/2025 21:00 |
Not measured | No data | Not measured | No data | No data |
| Cardiff Centre Updated: 23/12/2025 20:00 |
30 Low (1) |
12 Low (1) |
No data | 18 Low (2) |
19 Low (2) |
| Cardiff Newport Road Updated: 23/12/2025 20:00 |
Not measured | 15 Low (1) |
Not measured | Not measured | 22 Low (2) |
| Chepstow A48 Updated: 23/12/2025 20:00 |
Not measured | 13 Low (1) |
Not measured | 18 Low (2) |
24 Low (2) |
| Cimla Road / Victoria Gardens Updated: 28/06/2024 09:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Cwmbran Crownbridge Updated: 23/12/2025 20:00 |
36 Low (2) |
6 Low (1) |
Not measured | Not measured | 20 Low (2) |
| Hafod-yr-ynys Hill Roadside Updated: 23/12/2025 20:00 |
Not measured | 15 Low (1) |
Not measured | Not measured | Not measured |
| Marchlyn Mawr Updated: 23/12/2025 20:00 |
47 Low (2) |
7 Low (1) |
Not measured | Not measured | Not measured |
| Nantgarw Road Updated: 23/12/2025 20:00 |
Not measured | 10 Low (1) |
Not measured | Not measured | Not measured |
| Narberth Updated: 23/12/2025 20:00 |
31 Low (1) |
6 Low (1) |
0 Low (1) |
12 Low (2) |
14 Low (1) |
| Newport M4 Junction 25 Updated: 23/12/2025 20:00 |
27 Low (1) |
7 Low (1) |
Not measured | Not measured | Not measured |
| Newport M4 Junction 25 West Updated: 23/12/2025 20:00 |
Not measured | 7 Low (1) |
Not measured | Not measured | Not measured |
| Newport St Julians Comp School Updated: 23/12/2025 20:00 |
Not measured | 8 Low (1) |
Not measured | 17 Low (2) |
21 Low (2) |
| Port Talbot Dyffryn School Updated: 23/12/2025 19:00 |
Not measured | Not measured | Not measured | 10 Low (1) |
10 Low (1) |
| Port Talbot Little Warren Updated: 23/12/2025 20:00 |
Not measured | Not measured | Not measured | 11 Low (1) |
10 Low (1) |
| Port Talbot M4 Junction 41 Updated: 23/12/2025 20:00 |
Not measured | 8 Low (1) |
Not measured | Not measured | Not measured |
| Port Talbot Margam Updated: 23/12/2025 20:00 |
30 Low (1) |
10 Low (1) |
1 Low (1) |
7 Low (1) |
11 Low (1) |
| Port Talbot Prince Street 2 Updated: 23/12/2025 20:00 |
Not measured | Not measured | Not measured | 10 Low (1) |
10 Low (1) |
| Rhondda Glyncoch Garth Avenue Updated: 23/12/2025 20:00 |
Not measured | Not measured | Not measured | 16 Low (2) |
19 Low (2) |
| Rhondda Mountain Ash Updated: 23/12/2025 20:00 |
Not measured | 12 Low (1) |
Not measured | Not measured | Not measured |
| Rhondda Pontypridd Gelliwastad Rd Updated: 22/12/2025 18:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Rhondda-Cynon-Taf Broadway Updated: 22/12/2025 07:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Rhondda-Cynon-Taf Pontypridd A470 Updated: 23/12/2025 20:00 |
Not measured | 16 Low (1) |
Not measured | Not measured | Not measured |
| Swansea Cwm Level Park Updated: 24/01/2025 13:00 |
No data | No data | Not measured | Not measured | Not measured |
| Swansea Hafod DOAS Updated: 25/01/2025 18:00 |
No data | No data | Not measured | Not measured | Not measured |
| Swansea Morfa Road NOX Updated: 23/01/2025 20:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Swansea Morriston Roadside Updated: 14/11/2024 15:00 |
No data | No data | Not measured | No data | Not measured |
| Swansea Port Tennant Roadside Updated: 31/01/2025 12:00 |
Not measured | No data | Not measured | No data | Not measured |
| Swansea Roadside Updated: 23/12/2025 20:00 |
Not measured | 19 Low (1) |
Not measured | 10 Low (1) |
13 Low (1) |
| Swansea St Thomas DOAS Updated: 25/01/2025 18:00 |
No data | No data | No data | Not measured | Not measured |
| Swansea Station Court High Street Updated: 31/01/2025 13:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Wrexham Updated: 23/12/2025 20:00 |
Not measured | 29 Low (1) |
1 Low (1) |
20 Low (2) |
25 Low (2) |
| Wrexham A483 Updated: 23/12/2025 05:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Wrexham Chirk Updated: 23/12/2025 20:00 |
Not measured | 26 Low (1) |
Not measured | 14 Low (2) |
30 Low (2) |
| Wrexham Chirk Community Hospital Updated: 23/12/2025 20:00 |
Not measured | 8 Low (1) |
Not measured | 12 Low (2) |
21 Low (2) |