Why do we have summer and winter? Why when we are freezing, people are swimming on the other side of the Earth? In this article, we explain in simple terms that seasons are not caused by the Earth's distance from the Sun, but by a "tilt" that changes everything. You will learn how this tilt of our planet distributes light and warmth, creating the cycle of life we call seasons.
What Are Seasons and Why Do They Exist?
A simple guide to understanding how weather changes throughout the year
Most of us associate seasons with specific images: the flowers of spring, the warm seas of summer, the yellow leaves of autumn, and the cold of winter. But have you ever wondered why this change happens? Why doesn't the weather stay the same all year round? The answer is not found in how close we are to the sun, as many believe, but in the way the Earth "stands" in space as it revolves around it.
1. The Myth of Distance
Before we see the truth, let's debunk a misconception: Many people think that summer is hot because the Earth gets closer to the Sun, and winter is cold because it moves away. This is not true. In fact, when we in Greece have winter (January), the Earth is at its closest distance from the Sun! The reason the weather changes is the Earth's "tilt".
2. It All Starts with a "Tilt"
Imagine the Earth as a spinning top rotating around itself. However, this top is not standing upright. It is slightly tilted to one side. This tilt (about 23.5 degrees) is the reason seasons exist.
- When the Earth tilts toward the Sun: The part of the planet that is "tilted" toward the sun receives its rays more directly and for more hours. There we have Summer.
- When the Earth tilts away from the Sun: The rays fall at an angle, they are more "weak" and the day gets shorter. There we have Winter.
3. Why Are Seasons Different in Other Places?
Because the Earth is a sphere, when the top part (Northern Hemisphere, where Greece is located) tilts toward the sun, the bottom part (Southern Hemisphere, where Australia is located) necessarily tilts away from it.
That's why when we celebrate Christmas with coats and snow, in Australia they celebrate Christmas on beaches with heatwaves. Seasons are always opposite in the two halves of the planet.
4. What Happens at the Equator and the Poles?
The weather doesn't change the same way everywhere:
- In the middle of the Earth (Equator): Because it's always in the center, the sun hits them almost the same all year. There they don't have four seasons, but almost permanent summer.
- At the edges of the Earth (Poles): There the seasons are extreme. In summer the sun never sets (the day lasts 6 months!) and in winter it never rises (night for 6 months!).
5. The Importance of Spring and Autumn
These two seasons are the "intermediate stations". They occur when the Earth is neither tilted toward nor away from the sun, but somewhere in between. During the equinoxes (around March 21 and September 23), day and night are almost equal everywhere on the planet.
6. How Does the Tilt Affect the Weather?
The tilt doesn't just change temperatures. It affects:
- The duration of day and night
- The intensity of sunlight
- Which winds blow and where it rains
- Plant and animal cycles (flowering, migration, hibernation)
Conclusion
Seasons are not a mystery. They are the natural result of a simple fact: our planet doesn't stand "straight" as it travels around the sun. This small tilt, just 23.5 degrees, is enough to create all the weather changes that govern life on Earth. Next time you see the leaves fall or the first flowers bloom, remember that you are witnessing the eternal dance between Earth and Sun, a dance that has been going on for billions of years and will continue for billions more.
