Weather Vanes and Wind Socks: Decor and So Much More

Despite their name, "weather" vanes are actually used for measuring winds -- more specifically, wind direction

Now that we know what weather vanes measure, let's explore how they measure it.   

How Weather Vanes Work

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The chicken or rooster is a classic weather vane shape. David Buffington/Photographer's Choice/Getty

Traditional weather vanes are made up of only a few parts: a vane, a mast, directionals, and an ornament. The vane is usually arrow-shaped, and like an arrow, has a front "tip" and a back "tail." When the wind blows, it pushes the tail (which has a larger surface area) until it is out of its path. The vane rotates freely and the pointer tip now aims in the opposite direction -- the direction the wind came from. The directionals stay still on the mast; match the tip to whichever directional it points towards and you've got your wind direction! 

It's a very simple mechanism. Of course, it only works properly if the wind flows freely and isn't blocked by buildings, trees or plants. This is the very reason why weather vanes are always placed atop high buildings and church steeples. 

One of the oldest wind vane ornament designs is the chicken or rooster shape. Today, they come in all shapes and sizes, but the most common designs remain chickens, ships, and arrows. In fact, the tallest US weather vane is in the shape of a ship. If you ever find yourself near the area, the 48-foot-tall gold and vane is hard to miss!

Remember This About Wind Directions

Wind direction may not seem like the most useful of weather measurements, but it actually tells a great many things about weather. Let's say that you're standing at the center of Dallas, Texas with the Gulf to your south; the warm and humid southern states to your east; cooler and drier air from the Plains to the north; and the desert climate to the west. Based on this, a north wind will bring cooler and drier air to Dallas, a wind from the south will bring moist coastal air, so on and so forth. In this way, noting the wind direction gives you an idea of what type of air mass is moving in. Similarly, a sudden change in wind direction also indicates that a low pressure area or weather front is passing by.   

Always remember: wind direction is recorded as the direction FROM which the wind blows. What's more, wind will always blow from that direction towards the exact opposite direction. For example, a northerly wind would be one that blows from the north to the south. 

It can be reported in cardinal directions or in degrees. 

  • North (0°)
  • Northeast (45°)
  • East (90°)
  • Southeast (135°) 
  • South (180°)
  • Southwest (225°)
  • West (270°)
  • Northwest (315°)

Wind Vanes vs. Wind Socks

Low Angle View Of Windsock Against Clear Sky
Wind vanes also measure wind direction (and give a broad indication of speed). Laszlo Prising / EyeEm / Getty Images

Windsocks, conical orange-and-white-striped tubes made out of fabric (hence the name "sock"), serve the same purpose as wind vanes. They measure the direction from which the wind is blowing.

Although their bright colors make them look less "official", they're actually used by the Federal Aviation Administration (FAA) to measure winds at airports. As the wind blows, the sock catches the wind and is filled with air which makes it lift and extend outward. Because meteorologists describe wind direction using the direction from which winds blow or originate from, the wind direction will always be the direction opposite from whichever way the windsock is pointing. 

Unlike wind vanes, wind socks can also be used to indicate general wind speed. In low winds, the windsock droops and flies close to its mounting pole. However, when the sock flies straight out and at a large angle to the pole, it's a pretty good indication that winds are strong.

Upgraded and Upstaged by the Anemometer

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Terry Wilson/E+/Getty Images

If it's an actual wind speed value you're after, though, you'll want to forego the wind sock for an anemometer.

Anemometers measure wind speed by capturing air flow in their cups, which then turn the shaft at a rate proportional to the wind speed. In the 1990s they were outfitted to measure wind direction, too, but rather than this being directly observed as is the case with vanes or socks, it is computed from the cyclical changes in cupwheel speed. 

In truth, the dual capability of anemometers to measure both wind direction + speed is the reason why today's wind vanes are more often used as architectural decor than as functional weather instruments. 

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Means, Tiffany. "Weather Vanes and Wind Socks: Decor and So Much More." ThoughtCo, Oct. 24, 2016, thoughtco.com/weather-vanes-and-wind-socks-4105822. Means, Tiffany. (2016, October 24). Weather Vanes and Wind Socks: Decor and So Much More. Retrieved from https://www.thoughtco.com/weather-vanes-and-wind-socks-4105822 Means, Tiffany. "Weather Vanes and Wind Socks: Decor and So Much More." ThoughtCo. https://www.thoughtco.com/weather-vanes-and-wind-socks-4105822 (accessed December 15, 2017).