AP Style holds to the general rule of lowercasing compass directions and capitalizing regions. For example,
- The hurricane move north towards the Gulf Coast.
- I live to the west of Detroit Michigan.
- The West Coast has beautiful scenery.
- Settlers moved into the West.
AP Style states that when referring to the names of a nation, directions should be lowercased unless they are officially part of the country’s name. For example,
- The western United States is full of open land.
- The United States is allies with South Korea.
This same idea goes for referring to individual states and cities. Lowercase is preferred unless it is in the state’s name (South Dakota but southern Illinois). The only exception to this is when you are referring to widely known sections such as the South Side of Chicago or West Philadelphia. If you are unsure, it is advised to use lowercase.
For a more full discussion on when to capitalize directions, check out our full page on the subject.