Winter Precipitation Types Table
| Type | Falls as | Air profile | On contact | NWS definition |
|---|---|---|---|---|
| Snow | ice crystals, flakes | below freezing all the way down | piles softly | Precipitation in the form of ice crystals, mainly hexagonal, often agglomerated into snowflakes. |
| Sleet | ice pellets | warm layer aloft, deep cold layer below - refreezes before landing | bounces, sounds like rice on the window | Pellets of frozen or mostly frozen raindrops or refrozen partially melted snowflakes; usually bounce on impact. |
| Freezing rain | liquid rain | shallow warm layer aloft, freezing surface - no time to refreeze | glazes clear ice instantly | Rain that falls as a liquid but freezes into glaze upon contact with the ground. |
| Rain | liquid drops | warm all the way to the surface | just wets | liquid precipitation - no frozen stage survives the descent. |
The same storm can drop four different things depending on one invisible detail: the vertical temperature profile between the cloud and your driveway. Snow falls when the whole column is below freezing and vapor deposits straight into crystals. Sleet happens when snow melts partway through a warm layer aloft, then refreezes into ice pellets before landing - the NWS defines sleet as pellets of frozen or mostly frozen raindrops or refrozen partially melted snowflakes that usually bounce when they hit. Freezing rain is the dangerous middle case: liquid rain that survives a shallow warm layer and freezes into glaze on contact with the ground.
The table below lines up all four types with their NWS glossary definitions, the air profile that produces each, and what it does on contact. The hand test settles arguments: snow piles, sleet bounces and sounds like rice on a window, freezing rain coats surfaces in clear ice you can see through, and plain rain just wets. That coating - glaze - is why freezing rain, not snow, snaps power lines and glazes bridges: it adds weight to everything it touches at the exact temperature where nothing melts back off.
How to use
- Type what you see out the window - bounces, glazes, piles or wets - and the tool names the precipitation type and its profile.
- Use the table's air-profile column to read a forecast: shallow warm air means freezing rain, a deeper warm pocket means sleet, all-cold means snow.
- Note the contact temperature in the last column - it is the difference between the two types that both start as rain.
Frequently asked questions
What is the difference between sleet and freezing rain?
Both start as snow that melts into rain in a warm layer aloft - the difference is what happens next. Sleet refreezes in a deeper sub-freezing layer near the ground and lands as ice pellets that bounce; freezing rain stays liquid until it touches the surface and freezes instantly into a glaze. The NWS definitions split them exactly this way: sleet is pellets of refrozen rain or partially melted snowflakes, while freezing rain is rain that freezes into glaze on contact with the ground. Sleet is a nuisance; freezing rain is the one that snaps power lines.
Why does freezing rain form instead of snow or sleet?
It is all about the depth of the warm layer. Snow needs the whole column below freezing. Add a shallow warm nose aloft and the snow melts but has no time to refreeze - it lands as supercooled rain and glazes whatever it touches (freezing rain). Deepen that warm pocket and the melted drop has room to refreeze into a pellet before landing (sleet). Eliminate the cold air at the surface and it is just rain. Forecasters watch that vertical profile - often the difference between two counties twenty miles apart.
Is sleet dangerous to drive in?
Far less than freezing rain, but not harmless: sleet's bouncing pellets accumulate like tiny ball bearings, reducing traction, and heavy sleet can bury roads in a granular crust. The real driving danger in a sleet storm is what falls next - sleet and freezing rain often alternate as the warm layer pulses, and a sleet-covered road can glaze over in minutes if the profile shifts. The NWS reserves 'heavy sleet' for accumulation of half an inch of pellets or more, a relatively rare event.
What is glaze ice and why does it break power lines?
Glaze is the clear, dense ice freezing rain leaves behind - water freezing on contact builds transparent layers that cling to every surface and add weight the structure was never rated for: about 57 pounds per cubic foot - several times denser than fresh snow - and stuck fast rather than resting loosely. A half-inch of glaze on a power line adds enough load to snap it, which is why ice storms routinely cause more outages than heavier snowfalls.