SECTION 1
What's Happening?
The same sun is in the sky. So why does it feel like summer has SO much more sunshine than winter?
SECTION 2
Big Ideas
The sun gives us light during the daytime. That means daytime is the time when the sun is up in the sky.
But did you know that the number of hours of daylight changes during the year? Let's learn why!
Daylight Changes
It Happens Every Year
SECTION 3
Let's Try It!
Scientists look at the world and observe. That means they watch carefully and write down what they see. Let's be scientists!
- Look outside your window at 5 o'clock in the evening. Is it light or dark?
- Draw a picture of what you see. Use a yellow crayon for light and a blue crayon for dark.
- Do this again in a different season. Is it the same or different?
- Compare your pictures. What do you notice?
When we look at information that other people have collected, we can find evidence. Evidence means clues that help us answer a question.
Look at this chart. It shows how many hours of daylight a city gets in each season:
Look at the chart! Can you see that the summer bar is the tallest? That means summer has the most daylight. The winter bar is the shortest. That means winter has the least daylight.
SECTION 4
What We Found
Our evidence shows us something really cool! The amount of daylight is different in each season.
In summer, the sun comes up early in the morning and stays up late. We can get about 15 hours of daylight! That is a lot of time to play outside.
In winter, the sun comes up later and goes down earlier. We only get about 9 hours of daylight. That is why it feels dark so much of the day.
Spring and fall are in between. They each have about 12 hours of daylight.
This diagram shows us that the seasons go in a cycle. A cycle means something that happens over and over in the same order.
The daylight grows from winter to summer. Then it shrinks from summer to winter. Then it starts all over!
SECTION 5
Can You See the Pattern?
Scientists love to find patterns. A pattern is something that happens the same way again and again.
The change in daylight is a pattern! Every year, summer has the most daylight and winter has the least. This never changes.
Patterns are everywhere in nature! Look at these examples:
| What Happens | The Pattern |
|---|---|
| ☀️ Daylight hours | More in summer, less in winter — every year! |
| 🌅 Sunrise time | Earlier in summer, later in winter — every year! |
| 🌙 Moon shape | Changes from big to small and back — every month! |
| 🌳 Leaves on trees | Green in summer, fall off in autumn — every year! |
SECTION 6
Why Does This Matter?
People use what they know about daylight to solve problems!
Isn't it amazing? People AND animals pay attention to how much daylight there is!
SECTION 7
Words to Know
- Daylight — The time when the sun is up and it is light outside.
- Season — A time of year. The four seasons are winter, spring, summer, and fall.
- Pattern — Something that happens the same way again and again.
- Evidence — Clues or information that help us answer a question.
- Observe — To look carefully at something and notice what is happening.
SECTION 8
Show What You Know!
Question 1: Warm-Up
- A. Summer days have more hours of daylight than winter days.
- B. The Sun is broken in the winter so it does not shine as long.
- C. Mia's family goes to the park much later in the winter.
Show answer
Question 2: On Track
- A. The Sun always sets at the same time every day of the year.
- B. There are more hours of daylight in June than in December.
- C. There are more hours of daylight in December than in June.
Show answer
Question 3: On Track
- A. Each day still has 24 hours, but there are fewer hours of daylight.
- B. Each day has fewer than 24 hours in the fall.
- C. The clocks run faster in the fall so the day ends sooner.
Show answer
Question 4: Challenge
- A. Every month always has exactly the same amount of daylight.
- B. The amount of daylight increases from winter into summer.
- C. July has less daylight than January because it is too hot.
Show answer
SECTION 9