The tilt of the Earth's axis.In the Summer, the northern hemisphere is tilted towards the sun, therefore it is hotter because the sun's rays hit the earth's surface more directly.
In the winter, the northern hemisphere is titled away from the Sun, which means that the sun's rays hit the Earth's surface in a slanted manner. Temperature is lower because of this.
Decreasing because when you travel west you will lose time. hopes this helped :)
The poles receive more direct sunshine so it has to do with the angle that the light hits. The Earth is round and when light hits it the light wraps around the earth. At the poles the light is very stretched and at the equator it is very direct hence it is hotter at the poles.
