Here's why:

* Wind direction is described by the direction the wind is coming *from*: So a westerly wind is blowing from the west.

* Degrees are measured clockwise from north: This means:

* North is 0 degrees.

* East is 90 degrees.

* South is 180 degrees.

* West is 270 degrees.

Important note: In some contexts, the direction of the wind might be expressed as "blowing towards 270 degrees" to clarify that it's blowing *towards* the west. However, the standard way to describe a westerly wind is "from 270 degrees".