Bewolking — 2020
| Month | Vlieland | Harlingen | Difference |
|---|---|---|---|
| Jan | 81.2 % | 81.5 % | -0.3 |
| Feb | 72.1 % | 71.9 % | +0.2 |
| Mar | 47.8 % | 48.3 % | -0.5 |
| Apr | 45.7 % | 45.4 % | +0.3 |
| May | 44.6 % | 45 % | -0.4 |
| Jun | 65 % | 65.7 % | -0.7 |
| Jul | 61.9 % | 61.6 % | +0.3 |
| Aug |
| – |
| – |
| – |
| Sep | – | – | – |
| Oct | – | – | – |
| Nov | – | – | – |
| Dec | – | – | – |