This image shows how often and how strongly the wind blows from different directions over a normal June. The biggest spokes point in the directions the wind most commonly blows from and the shade of blue indicates the strength, with dark blue showing the strongest winds. It is based on 1601 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Zandvoort, located 15 km away (9 miles). There are too few recording stations world wide to use actual wind data. Invevitably some coastal places have very localized wind effects that would not be predicted by NWW3.
According to the model, the prevailing wind at Zandvoort blows from the NNW. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Zandvoort. Converseley, dominant spokes represent favoured directions, and the more dark blue, the stronger the wind. Spokes point in the direction the wind blows from. During a typical June, the model suggests that winds are light enough for the sea to be glassy (the lightest shade of blue) about 10% of the time (3 days each June) and blows offshore 26% of the time (3 days in an average June). Over an average June winds exceeding >40kph (25mph) are not expected, but 1 have winds on the range 30-40 (19-25) at Zandvoort
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.