Seasons

Earth · weather · cycles · light

Earth's tilt matters. Seasons happen because Earth is tilted on its side as it orbits the Sun. When your part of Earth tilts toward the Sun, it gets more sunlight and warmth (summer), and when it tilts away, you get less sunlight and cold (winter).

Daylight changes daily. The number of hours of daylight changes throughout the year. Summer has the longest days, winter has the shortest days, and spring and fall are in between.

Animals respond to seasons. When seasons change, many animals either hibernate (sleep through winter) or migrate (travel to warmer or colder places). Birds might fly south, and bears might go into their caves to sleep all winter long.

Plants take their cues. Plants know when to grow new leaves in spring, make flowers in summer, drop leaves in fall, and rest in winter. They sense the changing daylight and temperature to know what season it is.

Different cultures count differently. Not everyone around the world defines seasons the same way. Some cultures have three seasons or five seasons instead of four, depending on what weather patterns matter most to them.