Answer:
Summers are caused by the rotation of the Earth on its axis, as well as its movement around the Sun.
Step-by-step explanation:
The Earth has a tilted axis, meaning it is not straight up and down as maps often picture it. This means that sunlight hits different parts of the Earth differently. If I were in North America and you were in South America, we would both be on the same side of Earth. But the temperatures and weather could vary. As Earth travels around the Sun, it gets steadily closer, or farther away. This heats up and cools the planet, therefore causing seasons.