Sheesh, I gotta admit that I'm not the sharpest pencil in the box, so if my math is off somewhere, please let me know. But I really started wondering: Where does northern Maine start?

So. Lets assume the following facts:

Kittery (Maine's southernmost point?) is located at longitude N43.05
Fort Kent (Maine's northernmost point?) is located at longitude N47.15.
Since there are 60 minutes of longitude per degree, there are 250 minutes of longitude between Kittery and Fort Kent.

So the halfway point between Kittery and Fort Kent (the dividing line between northern and southern Maine) would be longitude N43.05 plus 125 minutes of longitude, or longitude N45.10. What is at N45.10? Lagrange, about 5 miles south of Milo (sorry Sudonim), or about 25 miles north of Bangor.

So... Bangor is in southern Maine.