Bewolking — 2020
| Monat | Vlaardingen | Schiedam | Unterschied |
|---|---|---|---|
| Jan | 77.1 % | 77.9 % | -0.8 |
| Feb | 73.4 % | 73.8 % | -0.4 |
| Mär | 52.7 % | 53.2 % | -0.5 |
| Apr | 37 % | 37.7 % | -0.7 |
| Mai | 45.8 % | 46.5 % | -0.7 |
| Jun | 64.5 % | 65.7 % | -1.2 |
| Jul | 60.3 % | 62 % | -1.7 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Okt | – | – | – |
| Nov | – | – | – |
| Dez | – | – | – |