Dangosir y lefelau presennol yn y tabl isod – yn dangos crynodiadau a, lle’n berthnasol, y mynegai a’r bandiau cyfatebol.
Lefelau Presennol
| 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: 31/10/2025 15:00 | Not measured | 24 Low (1) | Not measured | Not measured | Not measured | 
| Aston Hill Updated: 31/10/2025 15:00 | 73 Low (3) | 2 Low (1) | Not measured | Not measured | Not measured | 
| Caerphilly Islwyn Road Wattsville Updated: 31/10/2025 15:00 | Not measured | 22 Low (1) | Not measured | Not measured | Not measured | 
| Caerphilly White Street Updated: 31/10/2025 15:00 | Not measured | 16 Low (1) | Not measured | Not measured | 23 Low (2) | 
| Cardiff Castle Street Updated: 31/10/2025 09:00 | Not measured | No data | Not measured | 9 Low (1) | 22 Low (2) | 
| Cardiff Centre Updated: 31/10/2025 15:00 | 61 Low (2) | 13 Low (1) | 3 Low (1) | 6 Low (1) | 12 Low (1) | 
| Cardiff Newport Road Updated: 31/10/2025 15:00 | Not measured | 13 Low (1) | Not measured | Not measured | No data | 
| Chepstow A48 Updated: 31/10/2025 15:00 | Not measured | 21 Low (1) | Not measured | 6 Low (1) | 16 Low (1) | 
| Cimla Road / Victoria Gardens Updated: 28/06/2024 09:00 | Not measured | No data | Not measured | Not measured | Not measured | 
| Cwmbran Crownbridge Updated: 31/10/2025 15:00 | 70 Low (3) | 5 Low (1) | Not measured | Not measured | 17 Low (2) | 
| Hafod-yr-ynys Hill Roadside Updated: 31/10/2025 11:00 | Not measured | No data | Not measured | Not measured | Not measured | 
| Marchlyn Mawr Updated: 31/10/2025 15:00 | 80 Low (3) | 0 Low (1) | Not measured | Not measured | Not measured | 
| Nantgarw Road Updated: 31/10/2025 15:00 | Not measured | 21 Low (1) | Not measured | Not measured | Not measured | 
| Narberth Updated: 31/10/2025 15:00 | 80 Low (3) | 1 Low (1) | 1 Low (1) | 9 Low (1) | 17 Low (2) | 
| Newport M4 Junction 25 Updated: 31/10/2025 16:00 | 43 Low (2) | 34 Low (1) | Not measured | Not measured | Not measured | 
| Newport M4 Junction 25 West Updated: 31/10/2025 15:00 | Not measured | 4 Low (1) | Not measured | Not measured | Not measured | 
| Newport St Julians Comp School Updated: 31/10/2025 15:00 | Not measured | 8 Low (1) | Not measured | 6 Low (1) | 13 Low (1) | 
| Port Talbot Dyffryn School Updated: 31/10/2025 15:00 | Not measured | Not measured | Not measured | 7 Low (1) | 17 Low (2) | 
| Port Talbot Little Warren Updated: 31/10/2025 15:00 | Not measured | Not measured | Not measured | 6 Low (1) | 20 Low (2) | 
| Port Talbot M4 Junction 41 Updated: 31/10/2025 15:00 | Not measured | 28 Low (1) | Not measured | Not measured | Not measured | 
| Port Talbot Margam Updated: 31/10/2025 15:00 | 71 Low (3) | 10 Low (1) | 0 Low (1) | 6 Low (1) | 17 Low (2) | 
| Port Talbot Prince Street 2 Updated: 31/10/2025 15:00 | Not measured | Not measured | Not measured | 8 Low (1) | 19 Low (2) | 
| Rhondda Glyncoch Garth Avenue Updated: 31/10/2025 16:00 | Not measured | Not measured | Not measured | 7 Low (1) | 18 Low (2) | 
| Rhondda Mountain Ash Updated: 31/10/2025 16:00 | Not measured | 10 Low (1) | Not measured | Not measured | Not measured | 
| Rhondda Pontypridd Gelliwastad Rd Updated: 31/10/2025 07:00 | Not measured | 27 Low (1) | Not measured | Not measured | Not measured | 
| Rhondda-Cynon-Taf Broadway Updated: 30/10/2025 07:00 | Not measured | No data | Not measured | Not measured | Not measured | 
| Rhondda-Cynon-Taf Pontypridd A470 Updated: 31/10/2025 15:00 | Not measured | 21 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: 31/10/2025 15:00 | Not measured | 10 Low (1) | Not measured | 8 Low (1) | 19 Low (2) | 
| 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: 31/10/2025 15:00 | Not measured | 13 Low (1) | 3 Low (1) | 4 Low (1) | 8 Low (1) | 
| Wrexham A483 Updated: 31/10/2025 14:00 | Not measured | 6 Low (1) | Not measured | Not measured | Not measured | 
| Wrexham Chirk Updated: 31/10/2025 15:00 | Not measured | 28 Low (1) | Not measured | 9 Low (1) | 25 Low (2) | 
| Wrexham Chirk Community Hospital Updated: 31/10/2025 15:00 | Not measured | 11 Low (1) | Not measured | 8 Low (1) | 15 Low (1) | 
