Bewolking — 1999
| Month | Court-Saint-Étienne | Mont-Saint-Guibert | Difference |
|---|---|---|---|
| Jan | 78.2 % | – | – |
| Feb | 77.4 % | – | – |
| Mar | 78.4 % | – | – |
| Apr | 63.7 % | – | – |
| May | 65.7 % | – | – |
| Jun | 56.5 % | – | – |
| Jul | 53.7 % | – | – |
| Aug | 71.1 % | – | – |
| Sep |
| 63.2 % |
| – |
| – |
| Oct | 61.8 % | – | – |
| Nov | 76.1 % | – | – |
| Dec | 80.1 % | – | – |