The months April-June and September-October are the best times to visit. July and August are generally very hot, and it can be a bit cool in October in the higher elevations and in the north. Sweaters or jackets are often needed for evenings.
Winter, though generally mild along the Mediterranean coast, can be rainy, foggy and windy inland and along the Atlantic coast. We think winter is on the cool side, and downright cold at higher elevations.