Temperatuur — 2026
| Monat | Haarlem | Velsen | Unterschied |
|---|---|---|---|
| Jan | 3 °C | – | – |
| Feb | 5.4 °C | – | – |
| Mär | 8.6 °C | 8.4 °C | +0.2 |
| Apr | 10 °C | 9.4 °C | +0.6 |
| Mai | 13.5 °C | 13 °C | +0.5 |
| Jun | 17.8 °C | 17.1 °C | +0.7 |
| Jul | 19.2 °C | 19 °C | +0.2 |
| Aug |
| 20.3 °C |
| 19.4 °C |
| +0.9 |
| Sep | – | – | – |
| Okt | – | – | – |
| Nov | – | – | – |
| Dez | – | – | – |