I was playing with this mod in a singleplayer pack of mine, and my base was in a snow biome.
It was snowing, and I was processing ore + making some sticks with the sawmill.

To my surprise, the snow on the top of the sawmill remained there.

I think it would make sense for a machine powered by hot air, that automatically transfers hot air upwards, to melt snow that happens to be on-top of it. Or perhaps, even near it.