Often implies a movement towards a specific northern destination or area within a country. Every winter, birds migrate up north.
Pro Tip 2/3
Cultural Identity
Can suggest a lifestyle or community typical of the northern region being referenced. They embrace the cold living up north.
Pro Tip 3/3
Geographic Relative
Its meaning can vary depending on the speaker's current location; more north than one's current position. I'm down south now, but I'll head up north soon.