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What is frost?

Weekly Quest No. 5 · Frost Hunters. A frost hunt walk, frost in a can, frost feathers and a stamp card. JK to Grade 8, 30–45 minutes.
Fallen autumn leaves edged with white frost crystals, a bright orange tulip-tree leaf in the middle.
Fallen autumn leaves edged with white frost crystals, a bright orange tulip-tree leaf in the middle.

WEEKLY QUEST · No. 5 · FROST HUNTERS

MoveMakeExplore30–45 minutesJK–Grade 8Science · Nature

Explore: read this aloud

Four-frame comic: frost crystals on grass; on a clear night heat escapes from a car roof to the sky; invisible water vapour drifts to a cold leaf; the vapour turns straight into a feathery ice crystal.

Frost is ice that grows out of the air. Air holds water you can't see, called water vapour. On a clear, still night, heat escapes to the sky, and grass and car roofs get colder than the air. They can dip below 0 °C even when the weather report says +2 °C. Most frost grows when water vapour touches something that cold and turns straight into tiny ice crystals, skipping the water step. Sometimes dew forms first and then freezes.

The whoa moment: A can of salty ice turns white with frost on the outside, though nothing wet touched it. The frost came out of the air.

What's in the Quest

Move: Frost Hunt Walk

  1. Bundle up and head out early.
  2. Find frost on five different things.
  3. Look under a big tree. Frost or none?
  4. Walk back. Tell where you found the most.

Weather swap: No frost? Play Vapour Tag indoors: zoom like vapour, touch the cold blanket, freeze with your arms out like a crystal.

Make: Frost in a Can

  1. Peel the label off a metal can.
  2. Half-fill it with crushed ice.
  3. Add 4–5 tablespoons of salt. Stir well.
  4. Guess first. Then wait 5–10 minutes. No touching!

Good to know: It goes wet first, then white. That's normal! No frost? Add more salt and stir. Whole cubes and paper labels slow it down.

Make: Frost Feathers

  1. Look at frost up close (outside, or on the can).
  2. Find the spiky feather shapes.
  3. Draw them big with white crayon on dark paper.
  4. Or draw them on page 4.

For the littlest (JK and SK)

Find one frosty thing and one that isn't. Touch the frost with a mitten.

★ Go further (Grades 6–8, or anyone who wants more)

Run a fair test: one can with ice and salt, one with only ice and water. Record what each can's outside does at 0, 1, 2, 3, 5 and 10 minutes, and its temperature if you have a kitchen thermometer. Then learn the difference between the dew point and the frost point, and explain why grass under a big tree often stays clear of frost.

Safety: Use a can with a smooth rim, or tape the edge: cut rims are sharp. The salty ice can gets colder than 0 °C, so hold it with a cloth or mitt. Salt stings cuts and cracked winter skin. Dress warm for the walk.

Pick one, or do them all. Any order. Then stamp the card: I moved · I made · I explored · I told someone what I found.

What the pages look like

Page 2 of the printable: My Frost Hunt

Four printable pages: the grown-up page with every step, a record page, a Go further page in field-notes style, and a make page with the stamp card.

Curious Kite · All Quests · Change the method. Not the child.