This image describes how frequently and how strongly the wind blows from different directions over a normal July. The biggest spokes point in the directions the wind most commonly blows from and the shade of blue suggests the strength, with dark blue strongest. It is based on 1736 NWW3 forecasts of wind since since 2006, at 3hr intervals, for the closest NWW3 model node to Ilha, located 22 km away (14 miles). There are not enough 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 dominant wind at Ilha blows from the SSE. If the rose diagram shows a close to circular outline, it means there is no strong bias in wind direction at Ilha. By contrast, dominant spokes illustrate favoured directions, and the more dark blue, the stronger the wind. Spokes point in the direction the wind blows from. During a typical July, the model suggests that winds are light enough for the sea to be glassy (pale blue) about 23% of the time (7 days each July) and blows offshore 50% of the time (15 days in an average July). Over an average July winds exceeding >40kph (25mph) are not expected, but 1 have winds on the range 30-40 (19-25) at Ilha
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.