Ultimately, the temperature in an area depends on the amount of the Sun's energy reaching the surface in that area. The amount of solar energy in a given area is greater at the equator than in an equal area at the poles, which is why the equator temperature is warmer than the polar temperatures.
The amount of solar energy in a given area is greater at the equator than in an equal area at the poles, which is why the equator temperature is warmer than the polar temperatures.