Equator-based world generator

Using the (0,0) coordinates as a point of origin, I'd like a world generator that places cold climates at the furthest north and south of the equator. Beyond temperature distinctions, biomes can remain randomized for the time being. The generator would need multiple settings for admins and offline users to decide how quickly the world moves from hot climates to cold, in order to create larger maps.

I'm not sure what else a programmer would need to know for this to work how I'd like. Let me know if I'm missing anything.