I'd agree with "unpredictable".
We generally go the last two weeks in August, which usually has some spells of strong wind; one holiday it was extremely windy for 10 days out of 14. We have been the last week in October, when we had glorious sunshine and mostly flat calm seas - gorgeous. We've been for two weeks in July with no wind. Last year it was early August and only one day of strong wind. In the summer months, the temperatures are oppressive when there is no wind.
It is as difficult to forecast as the UK weather.
Try the weather link the Useful Links on this site which gives data for last year including the wind, and there are some other weather sites with historical data, but I am not sure whether that records the wind speed.
Arnaki