We were in Trapani in July/August and enjoyed the warm beach weather there, the blue sky and the great food.
There are very few foreign tourists in Trapani making the atmosphere very relaxed. There is a lot to look at in the city and going on day trips as well. On a nearby mountain you find Erice and medieval city. You have access to there from Trapani with a cable car or can drive there in your own car. It's wonderful and quiet up there and there is a fantastic view over Trapani, western part of Sicily and the sea form there.