Bewolking — 2026
| Month | Alphen aan den Rijn | Leiderdorp | Difference |
|---|---|---|---|
| Jan | 79.3 % | – | – |
| Feb | 80.7 % | – | – |
| Mar | 54.2 % | 55.8 % | -1.6 |
| Apr | 77.6 % | 78.3 % | -0.7 |
| May | 59.9 % | 57.7 % | +2.2 |
| Jun | 62.1 % | 59.4 % | +2.7 |
| Jul | 52.4 % | 52.7 % | -0.3 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Oct | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |