How do weather vanes predict weather?

Answer:
Although a weathervane does not show you the precise weather, you can interpret the weather from the direction of the wind.

In the Northern Hemisphere wind coming from the North usually brings colder weather because it is coming from the Arctic and from the South is warmer because it comes from the Equator.
The opposite is true for the Southern Hemisphere; North is warmer because it comes from the Equator and South is colder because it comes from the Antarctic.
Also, if the wind is coming from over a large body of water, especially an ocean, the weather will be wetter and bring clouds and often rain. If the wind is coming from over land, it tends to be dryer.
Even though these rules mostly apply, there are occasions on which they do not.
First answer by ID1280956265. Last edit by Jorkins. Contributor trust: 1 [recommend contributor recommended]. Question popularity: 2 [recommend question].