The weather is a difficult to predict thing, but some areas are more windy than others for sure.
North Sardinia can easily get up to 30 Knots even in full summer, even if the transfers from one location to the other are really small (3-5 Miles).
East Sicily and Capri-Amalfi coast in summer are very calm (0-10 Knots) and transfers are longer (10-15 miles).
West Sicily is calm, but can bring fresh airs (10-15 Knots), with a first transfer Sicily-Egadi islands fairly long (60 miles).