Brussels' mild maritime climate is unfortunately characterised by lots of grey, rainy weather. The warmest months are July and August when highs hover around 22°C (72°F), though they can also be the wettest. Winters are more predictable with plenty of rain and heavy-coat 'highs' of 4-7°C (39-45°F).
| Month | Temp (°C) | Rainfall (mm) | Humidity (%) | Sunshine (hours) |
| Jan | -1 - 4 | 66 | 2 | |
| Feb | 0 - 7 | 61 | 3 | |
| Mar | 2 - 10 | 53 | 4 | |
| Apr | 5 - 14 | 60 | 5 | |
| May | 8 - 18 | 55 | 6 | |
| Jun | 11 - 22 | 76 | 7 | |
| Jul | 12 - 23 | 95 | 6 | |
| Aug | 12 - 22 | 80 | 6 | |
| Sep | 11 - 21 | 63 | 5 | |
| Oct | 7 - 15 | 83 | 4 | |
| Nov | 3 - 9 | 75 | 2 | |
| Dec | 0 - 6 | 88 | 1 |