Answer:
latitude or location relative to large mountains ranges
Step-by-step explanation:
This a desert, so there aren't any oceans nearby to cause currents
Higher elevation means colder, and deserts are hot.
Latitude has to do with this area's location on the globe, so if this place is closer to the equator, that would explain why this place is so hot.
The location beside a mountain means that the mountains will stop clouds from going overtop of the desert here.
Either of the first two answer would logically work, but I am leaning towardds the latitude answer.