It probably cause tempreture to fall by 5 celcius. Take the example of caves in Malaysia. They dont get any sunlight at all for ages, but it is not freezing point in there.

In some parts of Dark Caves, Batu Caves the tempreture goes as high as 28 celsius. You will begin to sweat after 1 minute. In contrast the tempreture outside is only 23.

I do not know that there must be dust in the atmosphere to create rain. Can you explain, please.

We need sub zero to snow and we are not even near it yet.