How long will snow last in Japan?

I was thinking of visiting Japan in January-February but recon there are not much hiking options there by then, since all high peaks and the alps be covered in snow. Still I feel it interesting seeing onsen in snow and cold.

How long would snow expect to last in for instance Nyuto, Kusatsu, Manza, etc?

I guess peaks like mt Hakusan, mt Norikura, mt Rishiri are not able to be climbed until summer though?

Hi!

I can't speak for Kusatsu or Manza, but I expect Nyuto can have snow until April or May. I've been in snow in Kakunodate in March and I was in a blizzard near Towadako towards the end of April. (It was peak sakura in Kakunodate at the time and just past peak in Hirosaki.)

January and February tend to be the snowiest months in Japan.