Snow texture make FPS drop significanly

[Javel1n]

I create huge prison with lots of mods and land. I still built this prison. Right now, with almost finished ( all furnished, 50 worker, 200 cooker, 450 guard, 150 dogs, 20 armed guard ), i got "only" 15 - 20 FPS. But, when winter strike, i drop to unplayable FPS ( 5 - 10 FPS ). It is winter, because when i turned off the weather, i got a decent FPS, even with 2500+ prisoner ( 10 - 15 FPS ).

So, is there anyway to remove snow texture, but still retain weather fucntion ( heat + cold )?