Not to get super technical about it, but take the winter season as 1/4 of the year, which is 365 days.
That gives us 91.25 days to get snow.
But using your 95% figure, we don’t get snow on 95% of those days.
That leaves the remaining 5%, and we get roughly 4.6 snow days.
Well, if I’m being honest, I’d take my 4.6 snow days and run laughing all the way to the bank.