A diagram explaining the cause of the season shows the earth and its orbit around the sun. What is the main factor in how the changing seasons occur?

Answer 1

tilt of axis

Answer 2

A line between the earth north pole and south pole is inclined to the orbital plane of the earth around the sun at about 23 degrees. Therefore at summer solstice in June the north is getting more sun and it is directly overhead at noon if you are about 23 degrees above the equator (tropic of Cancer, summer solstice), a quarter year later the sun is hitting the earth right at the equator (fall equinox), another quarter around and the south is getting the sun, tropic of Capricorn below the equator, then in spring another equinox as we head for summer. ( try Sea Scouts :)

Answer 3

tilt of axis