Bewolking — 2020
| Month | Voorne aan Zee | Maassluis | Difference |
|---|---|---|---|
| Jan | 77 % | 77.1 % | -0.1 |
| Feb | 74.1 % | 73.4 % | +0.7 |
| Mar | 52.2 % | 52.7 % | -0.5 |
| Apr | 35.1 % | 37 % | -1.9 |
| May | 45.8 % | 45.8 % | +0.0 |
| Jun | 63.4 % | 64.5 % | -1.1 |
| Jul | 59.7 % | 60.3 % | -0.6 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Oct | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |