Seasons obviously are not caused by how close we are to the sun according to Perihelion (January 3, when the sun is closest to the earth) and Aphelion (July 4, when the sun is farthest from the earth) because these are complete opposites of how the seasons work! It's not hot January 3, and its definitely not cold July 4, so let's get into this. What does cause the seasons and why? Tilt matters a ton in this:Tilt: In the summer, the northern hemisphere is tilted towards the sun. a) This causes the sun to be higher in the sky and shine directly on us.b) This also causes the days to be longer than the nights so the earth heats up more than it coolsNOTE) When we have summer, the northern hemisphere has winterRevolution:Revolution of the earth around the sun, the tilt doesn't change, but since the earth revolves, the seasons do change.