How can it be “too cold to snow” when it snows on top of mountains and in countries with much colder climates?

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Where I am from (UK) people often say “it’s too cold to snow”. How can this be true when it snows in the Artic and on top of mountains?

In: Earth Science
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I wonder if they mean it’s too cold/DRY to snow. Like reported temperatures are more common than humidity.

They mean that the humidity is too low relative to the temperature for snow to occur

Not enough water in the air to snow

Cold air holds less water so it being to cold to snow is more about cold and dry conditions. Furthermore many colder climates such as the tops of mountains and the artic are snowy because the snow almost never melts but because the air there is dry they also don’t recieve that much snow.

Air is thinner higher up, meaning less humidity.

Too cold to snow just means its under 32 F (0 C) and the humidity is over 70%, creating frozen ice

It’s a commonplace saying in the UK, and although it’s vaguely correct it’s not for reasons that would necessarily make sense elsewhere in the world.

The UK has a fairly unique climate, being at a northerly latitude on the western side of a major continent, but at the same time receiving the benefits of the Gulf Stream. This means that the UK is simultaneously far warmer than would be expected for somewhere at that latitude, and subject to significant amounts of rainfall.

The prevailing British weather comes in to the country as fronts from the Atlantic. These typically bring plenty of rainfall but also, due to the Gulf Stream’s effects, are relatively warm.

On rarer occasions the weather changes and weather fronts come in to the UK from the north. These weather fronts are typically far colder but because they haven’t travelled over a large ocean, are much less likely to bring rain.

So the TLDR for the above is that there are two main types of weather affecting Britain: warm and wet, or cold and dry. This means that in winter the coldest days are those associated with northern winds bringing bright, clear skies.

It’s not that it’s literally too cold to snow, it’s just that in the UK when it’s very cold, that’s rarely associated with the sort of clouds that also bring snow.

Consider Antarctica. It’s covered in literally miles deep glaciers and snow over the entire continent. So you’d think it must snow a lot there, but it doesn’t. It’s a desert. It’s one of the driest places on Earth. But any snow that does fall, doesn’t melt, and so it sticks around year after year, millennia after millennia.

Mountains tend to hold onto their snow as well, which is where mountain glaciers come from. It doesn’t have to snow often, it just has to stick around and not melt.

Mountains also tend to be complicit in rainfall patterns and act as natural barriers to water and rainfall. Moist air hits a mountain range and tends to dump all it’s rain on one side, and end up bone dry on the other. This also causes a bit more rainfall in parts of the mountains as well.

I always thought it was due to the fact when there is cloud cover likely for snow it feels warmer than a clear night, which is unlikely to snow.

You might want to check out [this Tom Scott video](https://youtu.be/p7I4xpSz6-Y) about this exact question

Here is a simpler thought experiment. Consider the water cycle. The water has to be warm to evaporate. Then the clouds move inland and either rain or snow. As soon as that cloud hits a cold patch it will drop it’s water. This will usually happen where it’s -5c the cloud will never make it to places of -30c because it already froze and fell out of the sky.