The Four Seasons: Spring, Summer, Fall, Winter - First Grade Science
Throughout the year, our planet experiences a predictable, repeating cycle of changes in weather, daylight hours, and plant growth called the seasons. The four seasons are spring, summer, fall (autumn), and winter. As the seasons change, the world around us transforms: trees sprout tender green leaves, burst into colorful autumn hues, or stand bare beneath snowy skies. By learning what causes the seasons and observing their distinct patterns, you discover one of the most magnificent rhythms in all of nature.
What Causes the Changing Seasons?
Many people guess that summer happens when Earth is closer to the sun, but that is actually incorrect! The true cause of the four seasons is the tilt of planet Earth as it travels around the sun.
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| EARTH'S TILT AND ORBIT |
| |
| [EARTH: Tilted Axis 23.5] |
| / |
| .' '. |
| / * \ |
| \ / |
| '._.' |
| / |
| |
| <--- EARTH ORBITS AROUND SUN (365 DAYS / 1 YEAR) ---> |
| |
| .--------------. |
| / SUN \ |
| | Light & Heat | |
| \ / |
| '--------------' |
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The Tilted Axis
Earth spins on an imaginary tilted line through its center called an axis. Earth's axis is tilted at an angle of 23.5 degrees. As Earth travels around the sun along its circular path (orbit) over the course of 365 days (one year), different halves of the Earth lean toward or away from the sun. When our half of the Earth (hemisphere) tilts toward the sun, we receive direct, concentrated sunlight and enjoy long daylight hours: this is Summer! When our half of the Earth tilts away from the sun, sunlight strikes us at an angle, spreading the heat out, and days are short: this is Winter!
The Four Seasons in Order
The seasons always follow the exact same sequential order, cycling smoothly from one into the next.
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| THE CYCLE OF SEASONS |
| |
| [ 1. SPRING ] |
| Warm breezes; flowers bloom; |
| baby animals are born. |
| | |
| v |
| [ 2. SUMMER ] |
| Hottest temperatures; longest |
| days; lush green trees. |
| | |
| v |
| [ 3. FALL ] |
| Cooler crisp days; leaves change |
| color; animals gather seeds. |
| | |
| v |
| [ 4. WINTER ] |
| Coldest temperatures; shortest |
| days; snow, ice, bare trees. |
| | |
| +-----> Back to Spring! |
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Spring: Rebirth and New Beginnings
Spring begins when the days start growing longer and warmer after the long chill of winter. Rain showers soak the thawing ground. Seeds awaken and sprout through the soil, buds swell on tree branches and open into pale blossoms, and migrating birds return from warm southern lands. Many animals, including rabbits, deer, and ducks, give birth to babies during spring because food is plentiful.
Summer: Sunshine and Abundance
Summer brings the warmest temperatures of the year and the longest daylight hours. The sun climbs high in the sky each afternoon. Trees are covered with dense, deep green foliage catching sunlight for photosynthesis. Fruit orchards ripen with peaches, berries, and melons. People wear lightweight shorts and hats, swim in cool pools, and enjoy outdoor games late into the evening.
Fall (Autumn): Harvest and Preparation
During fall, the days become noticeably shorter and the air turns cool and crisp. Deciduous trees stop making green chlorophyll, revealing brilliant red, orange, gold, and purple pigments in their leaves before shedding them to the ground. Farmers harvest pumpkins, apples, corn, and squash. Woodland animals like squirrels hurry about, gathering and burying acorns to prepare for the freezing winter ahead.
Winter: Rest and Cold
Winter is the coldest season, bringing freezing temperatures, biting winds, frost on windows, and snowfall across many parts of the world. The sun stays low in the sky, and nighttime arrives early in the late afternoon. Deciduous trees stand bare and dormant, conserving their energy. Water in shallow ponds freezes into solid sheets of ice, and people bundle up in thick wool coats, scarves, mittens, and warm boots.
Chapter Review Exercises
Question 1: What is the scientific cause of the changing seasons on Earth throughout the year?
Question 2: What happens to daylight hours and temperatures when our half of the Earth is tilted toward the sun?
Question 3: Describe two observable changes that take place in plant life during the autumn season.
Question 4: List the four seasons in their correct repeating cycle, starting with Spring.
Solutions and Explanations
Solution 1: The changing seasons are caused by the 23.5-degree tilt of the Earth's axis as it orbits around the sun over the course of one full year (365 days).
Solution 2: When our half of the Earth is tilted toward the sun, we receive direct, concentrated sunlight and experience longer daylight hours and warmer temperatures, creating the summer season.
Solution 3: In autumn, deciduous trees stop producing green chlorophyll, which allows brilliant hidden pigments of red, yellow, and orange to show in their leaves; later in the season, trees drop their leaves to conserve water and survive the coming cold.
Solution 4: The four seasons in their correct cycle are Spring, Summer, Fall (Autumn), and Winter.