Neerslag — 2020
| Month | Wassenaar | Katwijk | Difference |
|---|---|---|---|
| Jan | 82.7 mm | 69.1 mm | +13.6 |
| Feb | 136.9 mm | 126.9 mm | +10.0 |
| Mar | 46.1 mm | 45.3 mm | +0.8 |
| Apr | 26 mm | 25.5 mm | +0.5 |
| May | 19.7 mm | 16.9 mm | +2.8 |
| Jun | 66 mm | 64.4 mm | +1.6 |
| Jul | 80.5 mm | 71.2 mm | +9.3 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Oct | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |