When cool temperatures and wind is a concern, I use a thin, very light windshirt. If it is cold enough to need fleece, the windshirt comes off and the fleece goes on. I have a new, fairly densely woven fleece from Patagonia that offers some wind protection but not is not rain resistant. If more protection is needed, a light rain jacket or heavy rain parka goes on top of the fleece. Because at that point, the weather is usually cool enough that I can adjust the zippers on the fleece and jacket to prevent overheating. The windshirt adds almost no weight to my pack. When cycling on cool days, I often through the fleece over the windshirt at long stops.
Your needs will depend on the local climate, I live where it rains often but is usually not misty. In areas with persistent mist and dense fog, a different layering system might be better.