My Earth is not "tilted on its axis". The correct fact with which to introduce this discussion
is: The Earth's axis is not perpendicular to the plane of its orbit around the sun. It is directed
about 23.5 degrees from the perpendicular to that plane.
If the Earth's rotational axis WERE perpendicular to the plane of its orbit, then there
would be no seasons. The weather would be hottest at the equator, it would become
smoothly and steadily cooler as you moved farther from the equator, it would be coldest
at the poles, and at any fixed latitude, it would not change much throughout the year.