Book 4, Question 91
Why Do Icicles Hang From Roofs?
An icicle is meltwater that froze again on the way down! A warm patch of roof melts the snow. Then the drip hits cold air, and builds a hanging spike.
From the book
Page from A Million Whys Book 4
More fun facts
- An icicle is a hanging piece of ice made when dripping water freezes.
- Icicles form when water runs down a roof and freezes at 0 degrees Celsius or colder.
- Overnight, more drops flow down and freeze onto the ice that is already there, so the icicle grows.
- Ice needs something to freeze onto, as well as cold temperatures.
- You are most likely to see icicles on very cold winter days.
Sources: BBC, Science News Explores
Questions kids ask
Why are icicles pointy?
Each new drop runs down the icicle and freezes near the bottom, so it grows longer and thinner at the tip.