Why does snow crunch or squeak when you walk on it? Snow crunches in the cold because tiny ice crystals, which are rigid and not well-lubricated by water at low temperatures below ~14°F break and scrape against each other under pressure, creating a shattering or squeaking sound, unlike warmer snow where a thin water layer allows crystals to slide silently. The colder it gets, the harder the crystals are, the thinner the lubricating water, and the louder and more distinct the crunch. | Jeff Oechs