From what I understand, a great deal of coastal wind has to do with the temperature changes (and heat coeffecients) of different bodies. Land areas have a high gain and loss of heat rate. They cool rapidly in the evening, and warm rapidly during the day. The water on the other hand, is relatively consistent. What happens is throughout the day, the land heats up, causing the air to rise, and the cooler air over the water replaces it. (at least during an onshore breeze) From here on is a hypothesis, so I'm not sure if its correct. I suppose that this time of year, the land cools to about the same temp as the water during the evening, thus not too much wind. As the land heats up during the day, the wind picks up. As it cools again in the evening, it dies down again. This has been my experience for the most part, at least on the days when you wake up and its calm. This does not take into effect different pressures from weather systems, as well as the different effects of fronts and what not. So thats my theory, any others?