Rain and snow - what is precipitation?
Why do we sometimes get rain and sometimes get snow? These are different types of precipitation, but what does 'precipitation' mean?
When we talk about precipitation, we are talking about water that is falling out of the sky, this could be rain, drizzle, snow, sleet, hail or something rarer! But most of the time in the UK it's rain, so if you hear someone using the word 'precipitation' it probably means that the weather is going to bring a mix of different types (or phases) of water falling out of the sky, such as a mix of rain and hail.
It is important to know which type of precipitation the weather is going to bring as it can tell you about other things going on in the atmosphere, as well as what you might need to do, like taking an umbrella or getting ready to build a snowman!
Rain is the type of precipitation we see most of the time in the UK; it is water in its liquid state. Rain can come in lots of sizes, from big, heavy drops to light, little specs.
Drizzle is also water that falls out of the sky. The difference between rain and drizzle can be quite tricky to spot, but if you can feel drops, even little and light ones, this is rain, if you are getting wet, but can't feel the drops then that will be drizzle. You often get rain and drizzle mixed together and the best way to tell if drizzle is mixed in with the rain is by how far you can see; if it's not very far, and the rain isn't very heavy, then there will likely be drizzle mixed in with the rain.
Snow is one of the solid types of precipitation, this means that it is made of water that has been frozen. Snow occurs every winter in the UK, but some parts may not see snow every year.
Sleet is quite common in winter in the UK; it is a mix of rain and snow and occurs when it is too warm for just snow to fall.
Hail is another type of frozen precipitation, but unlike snow, which is quite soft, hail is hard and icy.
Other types of precipitation
There are other types of precipitation, but these are quite rare and some need very special conditions to occur. One of these is diamond dust, which is when tiny ice crystals form in the sky somewhere very cold; the name comes from its sparkly appearance.