Why We Have Seasons

Spring, summer, fall, and winter happen because Earth is tilted. Earth does not stand straight up as it goes around the Sun. It leans to one side by about 23.5 degrees. This tilt means that different parts of Earth get different amounts of sunlight throughout the year.

How the Tilt Creates Seasons

When the North Pole tilts toward the Sun, the Northern Hemisphere gets more direct sunlight. Days are longer and warmer. That is summer. Six months later, the North Pole tilts away from the Sun. Days are shorter and cooler. That is winter. Spring and fall happen in between.

Opposite Seasons

When it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere. This is because when one half of Earth tilts toward the Sun, the other half tilts away. So when kids in the United States are playing in the snow, kids in Australia might be at the beach.

Fun Facts

• Earth is actually closer to the Sun in January than in July, but the tilt matters more than distance.
• Places near the equator do not have big changes in seasons because they get steady sunlight all year.
• Uranus is tilted so much that it basically rolls around the Sun on its side.

Did You Know?

Without Earth's tilt, there would be no seasons at all. Every day would have about 12 hours of daylight and 12 hours of darkness everywhere.