Air Quality index, 28/05/2021 - 11/06/2021
| 28/05 | 29/05 | 30/05 | 31/05 | 01/06 | 02/06 | 03/06 | 04/06 | 05/06 | 06/06 | 07/06 | 08/06 | 09/06 | 10/06 | 11/06 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Conurbation | |||||||||||||||
| Brussels | 5 | 6 | 6 | 6 | 7 | 7 | 5 | 5 | 4 | 5 | 6 | 7 | 6 | 5 | 4 |
| Antwerp | 4 | 5 | 5 | 6 | 6 | 7 | 5 | 5 | 4 | 5 | 5 | 6 | 5 | 5 | 3 |
| Ghent | 5 | 5 | 6 | 6 | 7 | 7 | 5 | 5 | 4 | 5 | 6 | 6 | 5 | 4 | 3 |
| Liège | 4 | 5 | 5 | 6 | 6 | 6 | 5 | 5 | 4 | 5 | 5 | 7 | 7 | 6 | 4 |
| Charleroi | 4 | 5 | 5 | 6 | 6 | 6 | 5 | 4 | 3 | 5 | 6 | 6 | 7 | 5 | 3 |
| Area | |||||||||||||||
| Coast | 4 | 5 | 5 | 6 | 6 | 7 | 5 | 4 | 5 | 5 | 5 | 5 | 5 | 3 | 2 |
| West-Vlaanderen (south) | 4 | 5 | 5 | 5 | 6 | 6 | 5 | 4 | 5 | 5 | 5 | 5 | 5 | 4 | 2 |
| Ghent canal area | 5 | 5 | 6 | 6 | 7 | 7 | 5 | 4 | 4 | 4 | 6 | 6 | 5 | 5 | 3 |
| Oost-Vlaanderen (south) | 5 | 6 | 6 | 6 | 7 | 7 | 6 | 5 | 4 | 5 | 6 | 7 | 6 | 4 | 4 |
| Antwerp harbour area | 5 | 6 | 6 | 6 | 7 | 7 | 5 | 5 | 5 | 5 | 6 | 7 | 5 | 5 | 3 |
| Kempen - Vlaams-Brabant (east) | 4 | 5 | 5 | 6 | 6 | 6 | 5 | 5 | 4 | 5 | 6 | 6 | 6 | 6 | 4 |
| Limburg | 4 | 5 | 5 | 6 | 6 | 7 | 5 | 6 | 4 | 5 | 6 | 6 | 7 | 6 | 5 |
| Region | |||||||||||||||
| Brussels | 5 | 6 | 6 | 6 | 7 | 7 | 5 | 5 | 4 | 5 | 6 | 7 | 6 | 5 | 4 |
| Flanders | 4 | 5 | 5 | 6 | 6 | 7 | 5 | 5 | 4 | 5 | 6 | 6 | 6 | 4 | 3 |
| Wallonia | 4 | 5 | 5 | 6 | 6 | 6 | 4 | 4 | 3 | 5 | 5 | 6 | 7 | 5 | 4 |
| Country | |||||||||||||||
| Belgium | 5 | 5 | 5 | 6 | 6 | 6 | 5 | 5 | 4 | 5 | 6 | 6 | 6 | 5 | 4 |
| 1 | exellent |
| 2 | very good |
| 3 | good |
| 4 | fairly good |
| 5 | moderate |
| 6 | poor |
| 7 | very poor |
| 8 | bad |
| 9 | very bad |
| 10 | horrible |