Temperatuur — 2026
| Month | Velsen | Haarlem | Difference |
|---|---|---|---|
| Jan | – | 3 °C | – |
| Feb | – | 5.4 °C | – |
| Mar | 8.4 °C | 8.6 °C | -0.2 |
| Apr | 9.4 °C | 10 °C | -0.6 |
| May | 13 °C | 13.5 °C | -0.5 |
| Jun | 17.1 °C | 17.8 °C | -0.7 |
| Jul | 18.8 °C | 18.9 °C | -0.1 |
| Aug |
| 19.3 °C |
| 19 °C |
| +0.3 |
| Sep | 17.7 °C | 17.1 °C | +0.6 |
| Oct | 14.2 °C | 13.5 °C | +0.7 |
| Nov | – | – | – |
| Dec | – | – | – |