What is the main function of the central nervous system?

Sensory. The nervous system contains the brain, spinal cord, sensory organs and all the nerves. These are responsable for controlling the body and communication between its parts and organs.

Well, both latitude and intensity of light affect temperature because, the higher the light intensity, the higher the temperature and since latitude is the measure of how close you are to the equator, then the closer to the equator you are, the higher the temperature is.