Bewolking — 2026
| Month | Heiloo | Castricum | Difference |
|---|---|---|---|
| Jan | – | 82.7 % | – |
| Feb | – | 78.4 % | – |
| Mar | 51.2 % | 55.9 % | -4.7 |
| Apr | 79.9 % | 81.3 % | -1.4 |
| May | 57.7 % | 57.7 % | +0.0 |
| Jun | 59.8 % | 59.8 % | +0.0 |
| Jul | 51.9 % | 51.9 % | +0.0 |
| Aug |
| 51.5 % |
| 51.5 % |
| +0.0 |
| Sep | 71.1 % | 70.6 % | +0.5 |
| Oct | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |