Home Geography for Primary Grades · Lesson XVI · Unit 4: Water, air and weather
16. Dew, frost, clouds, fog, rain, hail and snow
Goal: Your child explains dew, frost, clouds, fog, rain, hail and snow as vapor that has been cooled, and keeps a week of weather observations.
You'll need
- Early-morning grass (for dew) or a frosty window if it is cold
- A dark cloth or black paper chilled in the freezer, for catching snowflakes
- A magnifying glass
- A geography notebook (any notebook kept just for these lessons) and a pencil
What's in the book
The sun turns water on land and sea into vapor. When vapor is cooled, it becomes dew on the grass, or frost if the night is cold. High in the cool air it becomes clouds (fleecy feather-clouds, sunset clouds); low down, fog or mist. Cooled clouds give rain; frozen drops are hail; vapor that freezes before forming drops falls as snow, which keeps plant roots warm. The child observes and writes.
The lesson, step by step
Pearls on the grass
If you can, start early in the morning. Go out and look at the grass or a spider web.
We call this dew.
Ask: Where did these drops come from? (From the air. The vapor touched the cold grass and turned to water.)
Frost
Read about frost.
If the night is quite cold, the dew will freeze. It is then called frost.
On a cold morning, look at frost on a window or car. In warm weather, look at the frosty inside of the freezer instead. Your child draws the frost patterns, as the book suggests.
Clouds
Read about clouds. Go out and lie on a blanket to watch them.
Ask: Are there high, thin "feather-clouds" today? Big puffy ones? Do any change shape or melt away while you watch?
This evening, watch the sunset clouds. How do their shape and color change as the sun goes down?
Fog, rain, hail
Read the next part together.
When clouds are low down, near the earth, we call them fogs or mist.
SayWhen cloud drops get cold, they join into big drops and fall as rain. If the drops freeze as they fall, that is hail.
Snow
Read about snow. If it is snowing, catch flakes on a black cloth chilled in the freezer and look at them with a magnifying glass. Count the six points.
Ask: How does snow help plants in winter?
The shape of a raindrop
The book asks: What shape are the raindrops?
What we know now: small raindrops are round, like tiny balls, and big ones are flattened on the bottom like a bun as they fall. They are not really shaped like the teardrops we draw.
Weather notebook
Start a weather page: each day this week your child writes or draws what they notice (clouds, fog, rain, snow, dew, frost). At the end of the week, they write a few sentences about what they saw, as the book asks.
Afterwards
Keep the weather page going for a week or longer.
Answers to the book's problems
Dew comes from vapor in the air that touches the cold grass and leaves and turns into tiny drops. Dew waters the plants. Frost is dew that freezes on a cold night. Clouds are vapor turned into tiny drops or ice crystals high in the cool air. Fog or mist is a cloud low down near the ground. Rain falls when cloud drops gather into large drops; hail is drops that freeze as they fall; snow forms when the moisture freezes before it becomes drops. Snow keeps the roots of plants warm in winter, and when it melts it gives water to the ground and streams. Raindrops are small round balls (larger ones flatten as they fall).
Worked out for this site from the scan. If a number in your copy differs, trust the book.