The Temperature Profile Explorer
Every kind of precipitation begins as ice in the cloud. Pick a scenario below to see what happens to it on the way down.
Rain
The Precipitation Catalog
A quick reference for all six kinds of precipitation.
Rain
Liquid water drops that fall when the air is above freezing all the way from the cloud to the ground, so ice crystals melt completely.
Snow
Ice crystals that clump into snowflakes and never melt on the way down because the air is cold enough the whole way.
Sleet
Snow melts into rain in a warm layer, then refreezes into small, hard ice pellets in a deep cold layer near the ground.
Freezing Rain
Snow melts into rain and stays liquid because the cold layer near the ground is too thin to refreeze it â until it touches a cold surface and freezes instantly into a glaze of ice.
Hail
Balls of ice that grow layer by layer as strong winds inside a thunderstorm carry them up and down through the cold upper cloud again and again. See how below!
Drizzle
Very light rain made of especially tiny water droplets, usually falling from low stratus clouds. Gentle enough that it barely makes a splash.
How Hail Forms
Hail doesn't follow the temperature profile above â it grows inside powerful thunderstorms. Strong updrafts keep carrying it back up into the freezing upper cloud again and again, and each trip adds another icy layer, like the rings inside a tree. It keeps growing until it's finally too heavy for the updraft to hold â then it falls. The stronger the updraft, the more trips a hailstone can survive, and the bigger it can grow.
Did You Know?
A few surprising facts about precipitation.
Snowflakes almost always have six sides, because that's the natural shape water molecules form as they freeze into ice crystals.
No two snowflakes are exactly alike. With so many tiny water molecules arranging themselves in so many ways as a flake forms, the odds of two matching perfectly are incredibly small.
The largest hailstone ever officially recorded in the U.S. fell in Vivian, South Dakota in 2010. It measured about 8 inches across â roughly the size of a volleyball!
A raindrop isn't shaped like a teardrop. As it falls â sometimes at speeds up to 20 miles per hour â air pushes up on the bottom, flattening it into more of a hamburger-bun shape.
Read the Profile
Look at each air temperature profile and guess what falls. Score 3 out of 4 to master this lesson!