Golarion's equator is located south of the bottom of the Inner Sea region map. Golarion is the same size as Earth, and the horizontal line formed by the Mana Wastes loosely correlates to the Tropic of Cancer. The Arctic Circle is just north of the top of the Inner Sea region map.
I tend to think of the Inner Sea as Golarion's Mediteranean. Not quite a perfect analogue, but close enough. Especially when you consider the location of Osirion.