Have you ever wondered about the changes in weather that happen at the same times every year? The reason lies in the seasons.
Learn what the seasons are, why they happen, and how they’re different in other parts of the world with this lesson.
What Are the Seasons?
The seasons are four different times during the year with different types of weather. The four seasons are called spring, summer, autumn, and winter. Seasons change throughout the year because of the way the earth moves. The earth orbits, or travels around, the sun. As it orbits, it spins on its own axis, too. Imagine there was a straight pole that went through the center of the earth, from the North Pole to the South Pole; this is the earth’s axis.
But the earth’s axis doesn’t go straight up and down. The earth actually tilts to the side, so as it rotates around the sun, half of the earth is leaning toward the sun and half is leaning away. Earth’s orbit, its rotation on its axis, and its tilt are all reasons for the four seasons!Let’s take a look at each season as it is experienced in the U.S.
North America’s Four Seasons
Spring in the U.S. begins around the 21st of March and ends around the 21st of June. It’s the time of year when sunlight gets stronger because the angle of the sun gets higher. Days in spring get longer, and weather becomes warmer.
You’ll notice that trees begin to grow flower buds and leaves, and animals come out of hibernation. Spring often sees a lot of rain, too, giving new plants and flowers the water they need to grow.
Summer is the hottest time of the year in North America. From around June 21st to September 21st, the Sun is at its highest point in the sky and days get very warm. Plants have fully grown leaves and flowers are in full bloom. The weather tends to be a bit drier during this time of year, though thunderstorms can bring heavy rain.
Autumn, also known as fall, begins around September 21st and ends around December 21st in the U.S. It’s the time of year when trees begin to lose their leaves and flowers and vegetables die.
The days get shorter and the angle of the sun begins to get lower, making the sunlight weaker. Autumn days are often cool and crisp, and nights are cold.
Winter, which goes from December 21st to about March 21st in North America, is the coldest season of the year. All the leaves have fallen off deciduous trees (not evergreens) and many animals are hibernating or have moved south. Snow falls more often than rain, and the ground becomes frozen and hard.
The angle of the sun is the lowest of the year, making the sunlight weak, the days cold, and the nights frigid.
Not everyone has the same seasons at the same time of year. In the Southern Hemisphere, which is the part of the earth below the Equator, the seasons are the opposite.
When North America is having summer, it’s winter in South America!Weather also depends on how far you are away from the Equator. If you live very close to the Equator, there won’t be any difference between winter and summer. The further from the Equator you are, the more differences you will experience between winter and summer.
The seasons are four different times during the year with different types of weather. They are spring, summer, fall, and winter, and are caused by the earth’s orbit around the sun, its rotation on its axis, and its tilt.
The Northern and Southern Hemispheres experience opposite seasons, and how much difference between them depends on how far you are from the Equator.