There are five regions on the map.
Plains of Sarahdun (Level 1-20) - warm region
Icy Coast of Barradon (Level 21-40) - cold region
Desert of Ysuria (Level 41-60) - warm region
Wasteland of Korrn (Level 61-80) - cold region
Denaris, the stoney Valley (Level 81-100) - warm region