One type of an Air Mass
As a meteorologist you quickly learn the term Air Mass.
This term means an area of relatively flat and uniform terrain with the same temp and moisture content.
There are places in the world that are conducive for being air mass zones such as Siberia and the flat plains of Canada. However, the key is to remember that air masses move. Canada it is known as the Canadian High pressure center. This high pressure moves southeastward towards the United States all the time. This high pressure is made up of Continental Polar air which is dry because it’s over land and cold because it has polar air associated with it. This is best seen in the winter as the temps drop right behind a cold front which is associated with the high pressure from Canada. It is not uncommon for places in the Northern United States to see temps drop into the Negative 20F range because of this cold air mass. Also with the right conditions this high pressure is responsible for the freezing that occurs in Florida and the Southeast sometimes.