Bewolking — 2026
| Maand | Castricum | Heemskerk | Verschil |
|---|---|---|---|
| Jan | 82.7 % | – | – |
| Feb | 78.4 % | – | – |
| Mrt | 55.9 % | 53.4 % | +2.5 |
| Apr | 81.3 % | 79.4 % | +1.9 |
| Mei | 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 | 70.6 % | 69.8 % | +0.8 |
| Okt | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |