Global wind patterns
In the diagram to the right, the global wind patterns are shown by colors. The hot air is rising and pushing the air up while the cool air is sinking and pushing the air back down to earth. This ends up pushing the air in a circular pattern. Most of the hot air is at the equator and most of the cold air is at the poles
Local wind patterns
Since we live in Marin County, we are pretty close to the bay. The cold air and wind comes in from the bay, so Novato gets the cold wind from the bay almost daily. At night, the wind can get pretty strong. Mainly because we're surrounded by mountains so that when the wind comes in, its trapped in between the hills and stays there for a while.