A weather vane (or wind vane) is an instrument for measuring wind direction. It is a simple instrument, consisting of an arrow, or any figure, mounted on a rod. This rod moves in the direction of the wind when there is breeze. The front part of the vane is more or less pointed and the back end is wide, so that even the slightest breeze will move the vane. The arrow turns until the wind is equally distributed on either side of the weather vane, making the front part indicate the exact direction of the wind. Wind vanes are placed in open and high places to catch the wind.

Weather vanes are one of the oldest wind instruments used by man. The oldest wind vane has been traced to the Tower of Winds in Athens, Greece, and dates back to 48 BC. Over the centuries, weather vanes have been used as ornaments to display the icons of various cultures, religions and countries. At one point of time, these weather vanes were most likely used as flags, as the origin of the word vane seems to have come from the Anglo-Saxon word fane, which means flag.

Weather vanes have no doubt been used to represent patriotic feelings as depicted by the Federal Eagle and the Goddess of Liberty vanes. Weather vanes, even today, are used more as ornaments on buildings than for any other specific purpose. Even office buildings are sporting weather vanes with corporate logos etched on them. They can be custom designed, from the size of the vane, to the material used, and of course the design. Modern wind vanes are also mounted with an anemometer, a device for measuring the speed of the wind. They may also be connected to a remote reading station. Modern weather vanes are rust free and maintenance free.

Weather vanes are available in hundreds of models and designs. They can be crafted to suit the exact feature of the house, its location, and the unique taste of the customer. Weather vanes are available in wrought iron, aluminum, copper, brass, bronze or steel. They are made in different shapes ranging from simple arrows to shapes of animals, birds, humans, crests, exotic figurines, or a combination of these themes. Antique weather vanes are so much in demand that there are some dealers who specialize in recreating weather vanes to look like antiques. Though weather vanes are more popular for the country or farm look, they can add a graceful touch to any building. Weather vanes are also used as decorative items inside the house or even on desktops.