When air flow is channeled and restricted, the pressure rises and the velocity increases, this is called the venturi effect. Wind patterns can be compared to the movement of water in a stream. The wind patterns near large bodies of water are affected by heat gain, heat loss, and heat storage variations between land and water. In valleys, wind moves uphill during the day as the sun warms the air causing it to be less dense and at night air flows back down the valleys as it cools and becomes heavier. Wind direction and vegetation affects the level of humidity.
Water vapor is a gas that occupies in the same space as other gases.
Together all the gases constitute air. Water vapor flows from areas of higher vapor pressure toward areas of lower vapor pressure. Large bodies of water will tend to stabilize temperatures on the adjacent land. Trees and other vegetation cool the air around them. Sites with a more southern slope will be warmer than a flat site because radiation from the sun is more perpendicular to its surface.