Minecraft wiki entry for Snow, associated text: Snow naturally generates in snowy biomes – snowy plains, ice spikes, frozen oceans, snowy taiga, frozen river, snowy beach, grove, snowy slopes, jagged peaks and frozen peaks – and in the windswept hills biomes above y-level 120. Only blocks with direct access to the sky can generate snow layers naturally (with the exception of some snowy villages, which are intentionally made to generate extra snow in areas inaccessible to the sky).[1]