Snow only fell on the tops of mountains, and the harvest took place in hot weather, so this is probably a metaphor for cool, fresh water from a clean stream. If your language has no word for snow, consider "cool, fresh, clean water." (See: [[rc://en/ta/man/translate/figs-metaphor]])
Most translations translate this metaphor as a simile and change the order of the phrases. Rain was important to the Israelites because only small amounts of it fell, so a cloud without rain was useless and brought disappointment to the Israelites. AT: "The one who boasts ... not give is like clouds and wind without rain" or "The one who boasts ... not give is useless and a disappointment, like clouds and wind without rain" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-simile]])