how does westerly winds affect vancouver vs. halifax in the month of january?

Answer 1

A westerly off the ocean for Vancouver is a warm moist wind that means lots of rain and mild temperatures. Pacific currents flow North, so the water is warmer than the Atlantic.

But for Halifax, a westerly is blowing across land and the air isn't warm anymore. It is cold. Cold air blowing over a small body of water will pick up moister, but it will mean snow.