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: 20/03/2026 21:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Aston Hill Updated: 21/03/2026 03:00 |
82 Low (3) |
8 Low (1) |
Not measured | Not measured | Not measured |
| Caerphilly Islwyn Road Wattsville Updated: 20/03/2026 21:00 |
Not measured | 17 Low (1) |
Not measured | Not measured | Not measured |
| Caerphilly White Street Updated: 13/03/2026 07:00 |
Not measured | No data | Not measured | Not measured | 29 Low (2) |
| Cardiff Castle Street Updated: 08/11/2025 21:00 |
Not measured | No data | Not measured | No data | No data |
| Cardiff Centre Updated: 21/03/2026 03:00 |
48 Low (2) |
37 Low (1) |
1 Low (1) |
25 Low (3) |
33 Low (2) |
| Cardiff Newport Road Updated: 21/03/2026 03:00 |
Not measured | 27 Low (1) |
Not measured | Not measured | 47 Low (3) |
| Chepstow A48 Updated: 21/03/2026 03:00 |
Not measured | 11 Low (1) |
Not measured | 26 Low (3) |
31 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: 21/03/2026 03:00 |
55 Low (2) |
13 Low (1) |
Not measured | Not measured | No data |
| Hafod-yr-ynys Hill Roadside Updated: 21/03/2026 03:00 |
Not measured | 16 Low (1) |
Not measured | Not measured | Not measured |
| Marchlyn Mawr Updated: 20/03/2026 21:00 |
91 Low (3) |
4 Low (1) |
Not measured | Not measured | Not measured |
| Nantgarw Road Updated: 20/03/2026 21:00 |
Not measured | 54 Low (1) |
Not measured | Not measured | Not measured |
| Narberth Updated: 21/03/2026 01:00 |
90 Low (3) |
10 Low (1) |
1 Low (1) |
26 Low (3) |
35 Low (3) |
| Newport M4 Junction 25 Updated: 20/03/2026 22:00 |
No data | No data | Not measured | Not measured | Not measured |
| Newport M4 Junction 25 West Updated: 29/01/2026 14:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Newport St Julians Comp School Updated: 21/03/2026 03:00 |
Not measured | 13 Low (1) |
Not measured | 25 Low (3) |
34 Low (3) |
| Port Talbot Dyffryn School Updated: 14/03/2026 21:00 |
Not measured | Not measured | Not measured | No data | No data |
| Port Talbot Little Warren Updated: 20/03/2026 21:00 |
Not measured | Not measured | Not measured | No data | No data |
| Port Talbot M4 Junction 41 Updated: 20/03/2026 06:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Port Talbot Margam Updated: 21/03/2026 03:00 |
34 Low (2) |
9 Low (1) |
1 Low (1) |
18 Low (2) |
36 Low (3) |
| Port Talbot Prince Street 2 Updated: 20/03/2026 21:00 |
Not measured | Not measured | Not measured | No data | No data |
| Rhondda Glyncoch Garth Avenue Updated: 20/03/2026 22:00 |
Not measured | Not measured | Not measured | No data | No data |
| Rhondda Mountain Ash Updated: 20/03/2026 21:00 |
Not measured | 54 Low (1) |
Not measured | Not measured | Not measured |
| Rhondda Pontypridd Gelliwastad Rd Updated: 13/03/2026 07:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Rhondda-Cynon-Taf Broadway Updated: 16/03/2026 12:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Rhondda-Cynon-Taf Pontypridd A470 Updated: 20/03/2026 21:00 |
Not measured | No data | 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: 20/03/2026 21:00 |
Not measured | 67 Low (1) |
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: 16/03/2026 11:00 |
Not measured | No data | Not measured | 22 Low (2) |
Not measured |
| Swansea Roadside Updated: 21/03/2026 03:00 |
Not measured | 29 Low (1) |
Not measured | 24 Low (3) |
33 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: 20/03/2026 20:00 |
Not measured | 103 Low (2) |
Not measured | Not measured | Not measured |
| Wrexham Updated: 21/03/2026 03:00 |
Not measured | 12 Low (1) |
3 Low (1) |
29 Low (3) |
37 Low (3) |
| Wrexham A483 Updated: 20/03/2026 16:00 |
Not measured | No data | Not measured | Not measured | Not measured |
| Wrexham Chirk Updated: 20/03/2026 21:00 |
Not measured | No data | Not measured | No data | No data |
| Wrexham Chirk Community Hospital Updated: 17/02/2026 10:00 |
Not measured | No data | Not measured | No data | No data |