Temperatuur — 2026
| Month | Heemskerk | Castricum | Difference |
|---|---|---|---|
| Jan | – | 2.9 °C | – |
| Feb | – | 5.1 °C | – |
| Mar | 8.1 °C | 7.9 °C | +0.2 |
| Apr | 9.4 °C | 9.4 °C | +0.0 |
| May | 13.5 °C | 13.5 °C | +0.0 |
| Jun | 17.8 °C | 17.8 °C | +0.0 |
| Jul | 18.7 °C | 18.8 °C | -0.1 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Oct | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |