Where does “snieh” come from?

snieh (Old Czech) comes from Proto-Slavic sněgъ, from Proto-Balto-Slavic snáigas, from Proto-Indo-European snóygʷʰos, from Proto-Indo-European sneygʷʰ- — to snow.

Ancestry of “snieh”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	sněgъ	snow
2	Proto-Balto-Slavic	snáigas	snow
3	Proto-Indo-European	snóygʷʰos	snow
4	Proto-Indo-European	sneygʷʰ-	to snow

Every word from Proto-Indo-European sneygʷʰ- →

snieh — Etymology, Origin & Word History | Etymology Explorer