Bewolking — 2020
| Month | Zwijndrecht | Ridderkerk | Difference |
|---|---|---|---|
| Jan | 76.4 % | 78.3 % | -1.9 |
| Feb | 75.2 % | 74.4 % | +0.8 |
| Mar | 52.2 % | 52.9 % | -0.7 |
| Apr | 33.7 % | 36 % | -2.3 |
| May | 47.6 % | 47.2 % | +0.4 |
| Jun | 64 % | 65 % | -1.0 |
| Jul | 61.9 % | 62.3 % | -0.4 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Oct | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |