Temperatuur — 2020
| Maand | Heemstede | Haarlem | Verschil |
|---|---|---|---|
| Jan | 6.8 °C | 6.9 °C | -0.1 |
| Feb | 7.3 °C | 7.2 °C | +0.1 |
| Mrt | 6.9 °C | 6.8 °C | +0.1 |
| Apr | 10.2 °C | 10.1 °C | +0.1 |
| Mei | 12.5 °C | 12.3 °C | +0.2 |
| Jun | 16.5 °C | 16.4 °C | +0.1 |
| Jul | 16.9 °C | 16.7 °C | +0.2 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Okt | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |