Air Quality index, 04/11/2021 - 18/11/2021
| 04/11 | 05/11 | 06/11 | 07/11 | 08/11 | 09/11 | 10/11 | 11/11 | 12/11 | 13/11 | 14/11 | 15/11 | 16/11 | 17/11 | 18/11 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Conurbation | |||||||||||||||
| Brussels | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 3 | 3 | 2 | 3 | 3 | 3 | 4 | 3 |
| Antwerp | 4 | 4 | 2 | 3 | 4 | 5 | 5 | 4 | 4 | 3 | 3 | 3 | 5 | 4 | 4 |
| Ghent | 2 | 3 | 2 | 3 | 5 | 4 | 4 | 4 | 3 | 2 | 3 | 3 | 4 | 3 | 3 |
| Liège | 3 | 2 | 3 | 3 | 3 | 4 | 4 | 4 | 3 | 2 | 2 | 3 | 2 | 3 | 2 |
| Charleroi | 2 | 3 | 2 | 2 | 4 | 4 | 4 | 5 | 3 | 2 | 2 | 3 | 3 | 3 | 3 |
| Area | |||||||||||||||
| Coast | 4 | 4 | 3 | 4 | 4 | 3 | 4 | 4 | 3 | 3 | 3 | 3 | 3 | 3 | 4 |
| West-Vlaanderen (south) | 3 | 4 | 3 | 4 | 4 | 4 | 4 | 4 | 3 | 3 | 3 | 4 | 4 | 3 | 3 |
| Ghent canal area | 3 | 3 | 2 | 4 | 4 | 4 | 4 | 4 | 4 | 3 | 3 | 3 | 4 | 3 | 3 |
| Oost-Vlaanderen (south) | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Antwerp harbour area | 3 | 3 | 3 | 4 | 4 | 4 | 5 | 5 | 4 | 2 | 3 | 3 | 5 | 4 | 4 |
| Kempen - Vlaams-Brabant (east) | 3 | 2 | 3 | 4 | 3 | 3 | 3 | 4 | 3 | 2 | 3 | 3 | 4 | 3 | 3 |
| Limburg | 3 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 3 | 2 | 3 | 4 | 3 | 3 | 3 |
| Region | |||||||||||||||
| Brussels | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 3 | 3 | 2 | 3 | 3 | 3 | 4 | 3 |
| Flanders | 2 | 2 | 3 | 3 | 4 | 4 | 4 | 4 | 4 | 2 | 3 | 3 | 4 | 3 | 3 |
| Wallonia | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 4 | 3 | 2 | 2 | 2 | 2 | 2 | 2 |
| Country | |||||||||||||||
| Belgium | 2 | 2 | 3 | 3 | 3 | 4 | 4 | 4 | 3 | 2 | 3 | 3 | 3 | 3 | 3 |
| 1 | exellent |
| 2 | very good |
| 3 | good |
| 4 | fairly good |
| 5 | moderate |
| 6 | poor |
| 7 | very poor |
| 8 | bad |
| 9 | very bad |
| 10 | horrible |