Q. Can a child throw snowballs on Shabbos or make a snowman?
Can one use snow to block high winds from blowing through the bottom of a side door that does not close properly, during a very windy Shabbos?
A. Mekor Chaim (320: 13) rules that the melochos of dash (threshing) and boneh (building) are transgressed when making snow balls, and one should stop youngsters from making them during Shabbos.
Shemiras Shabbos K’ (16: 44) also maintains that making snow balls or snowmen, is prohibited during Shabbos. However, Piskei Teshuvos (320: n. 210) quotes Be’er Moshe (6: 30) that one does not have to stop minors from creating them on Shabbos.
Horav Shlomo Miller’s Shlit’a opinion is also that one should avoid making them. However, the Rov permits using snow to create a block to stop high winds from blowing through the bottom of a side door that does not close properly, during a very windy Shabbos.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a