VoxelMush. You surely could wait up. I'm quite sure that the next release (if not the very next, then soon enough) this thing will be "corrected".
In the develop section there is a post tittle something like "little random additions" in which the developer said it will be added a "single tile effect for weather". (seems that how the game works the snow/rain effects are likely a "layer" on top of all, getting all slowed down). With this addition, every tile of the map will change into "rainy/snowy" version of, which i assume will kill this lag we - the people using not so fast computers - suffer.
JEB Davis have just solved your question.
My advice... once it is updated, try to switch it on again.
Good trips!