How do you abbreviate northern?

There isn't a universally accepted abbreviation for "northern."

Here are some options depending on the context:

* N: This is commonly used in geographical contexts, like "N. Hemisphere" or "N. California."

* Nor: This is a less common abbreviation, but can be used in certain contexts, like "Nor. Lights."

* Nth: This is a less formal abbreviation and can be used in phrases like "the Nth part of the country."

Ultimately, the best abbreviation to use depends on the specific context.