The united states falls within which category of the world's nations?

Geothermic gradient is the rate of increasing temperature with respect to increasing the depth in the earths interior. away from tech tonic plates boundaries, it is about 25-40 c/km (72-87 degrees f/mi) of depth near the surface in most of the world.

Answerhave flowing water either episodically or during only a portion of the year;

Temperature, rainfall and relative humidity.